Renewed My Contract - confused and being overcharged

[#1]

I've been with Plusnet (Freeonline) since I started using the internet (many years ago) and have always felt I got a good deal when I rang up to renew my contract.  In January I rang and thought I'd sorted out a new 24 month contract.  I cant get Fibre so its unlimited broadband and line rental only.  I had to call back at the end of January as I received a bill notice of £31.11.

 My new contract dated 24 Jan email : 

Unlimited broadband service: £0.00 per month for 24 months then £11.88 per month
Line rental: £17.99 per month
Total £17.99 per month for 24 months on a new 24 month contract

My on line account product details show a charge of £17.99 for line rental and £11.66 yet My January & February bills have charged £21.22 for line rental plus £11.66.   I'm so confused.  Can someone help me here?  

[#2]

Hi Jackie,

I'm really sorry to see your bill's not right after renewing your contract with us.

I can see you've spoken with somebody this morning and this should be sorted now.

If you've got further queries though, feel free to get back to me and I'll be happy to help.