PN are charging me for their error

[#1]

I have been billed £1.96 for my Home Phone Call Features package i.e. Caller Display and
Anonymous Caller reject for the past 4 months. However, this month I have had an email stating
that PN have made and error for the past 4 months and should have charged me £4.99 per month
and they are going to charge me the extra on my next bill. I raised a ticket and stated that I
assumed the £1.96 per month was correct and had no reason to question it and felt that is was
unfair of PN to charge me for their error. PN would not give any ground on this, they insist I have
to pay for their error and, "I should have read the amended tariff" linked to the Service Notice
SN6733340; they have admitted that the incorrect charge was their fault:-
Excerpt of email from PN follows:
**************************************
Following our recent price changes the cost of your Home Phone calling
features should have been adjusted.
However, due to a temporary problem with our system this didn't happen,
and you were incorrectly charged for a feature bundle. I'm sorry for any inconvenience caused by this error.
*****************************************
Note the word "temporary" in the last paragraph; it took PN 4 months to find their error, and now
they are charging ME for their error.
I have been with PN for 2 years and this is my first real complaint I have hade with the service,
but because of this..............I could go on forever, words fail me.

[#2]

Hi Onlyme,
Firstly apologies for any distress that this information may have caused you.
As you have mentioned, it is our fault for incorrectly charging you less, however, it is within our right to recoup the charges that we did not make.  If this had happened the other way around, in that we were charging you £3 too much, I'm sure that you would expect us to amend our error as soon as possible.

[#3]

Sorry James but it not as clear cut as that and I don't know the legal situation, only I do know that for Council Tax there is a limited on under payment but not overpayment.

[#4]

Yes James, but if PN had charged me £3 extra, I would have picked up on it immediately, asked them to correct the error, and request a refund.  I would not have left it for 4 months.

[#5]

Surely you are only liable for the payment of invoices for services etc rendered?

[#6]

No - you're liable for the agreed cost of the services, even if not invoiced immeidately.  There's some time limits on it generally, but more than 3 months. 
I'd consider it as an interest free loan for four months.

[#7]

Was the OP explicitly notified of the cost of the service in advance - that's not clear to me.

[#8]

Yes, the exactly cost was referenced and advised that it would be charged on his next invoice date.

[#9]

I'm not clear if you are referring to the amount that should have been charged four months ago or the back payment amount for which he received notification recently. I was referring to the former.

[#10]

I'm not sure of the former.  The latter was notified of as per my above post.
The cost of ACR is documented on our website though.

[#11]

Somebody had better look in to the former because if he wasn't notified in advance of the cost you are on very dodgy ground claiming the back payments!

[#12]

Probably why other companies normally write off back charges after an increase as they have to prove the customer is aware of the charges for a service and therefore knownly being undercharged. If the customer believe they are being charged correctly and are hit by a bill sometime in the future for repayment of undercharging then they have an agrument that if they know the true charge at the time they would have cancelled or modify the service. 

[#13]

# Jelv , #itsme.  In reply to some of the above, I was not notified directly of the price increase of the
Anonymous Caller charge which was increased to £4.00 per month at the same time as
SN6733340 was issued in May 2009, although there was a link on the service notice leading to
the new tariffs.  As my next 3 months billing showed my Call Features as £1.96 per month, I
assumed this was correct and did not feel I had to check (PN are saying I was at fault here).
# James,  your reply No. 7.  Yes, I was notified, but only 4 months after the incorrect charging
was applied and PN are claiming 4 months back payment for their error.  You are inferring in your
reply that the error was discovered 1 month after the issue of SN6733340.
I would not be complaining if the error was discovered the following month after the price increase
and I would have just shrugged it off, but to leave the issue for 4 months and then charge the
customer for an error which should not have occurred in the first instance, I feel that PN are being
very unfair in charging me for their error.

[#14]

Could you post the contents of the service notice please.

[#15]

Quote from: Jameseh

I'm not sure of the former.  The latter was notified of as per my above post. The cost of ACR is documented on our website though.

but the web site has only just been corrected, it has been wrong since May