Daylight Robbery Help!!

[#1]

So annoyed at the moment!! When I signed up with Plus net the guy on the phone said if I chose to cancel at any time all I would have to pay for was the router which was 40 pounds. Now I'm being told its 105 pounds because I didn't pay the connections fee, which of course is wrong!!! I paid it and have proof on my credit card statement. Of course the staff I speak to are no use at all! Please can someone offer me advice!!! I don't know how to fight this. I really cannot afford to pay it.

[#2]

Welcome to the helpful forum
got to view my transaction  https://portal.plus.net/my.html?action=view_transactions&s=0
go down to the bottom of the list and that should show what you paid, click on the red number and that will give the details

[#3]

Thanks Pierre
It shows I did pay an initial set up fee so they must not have even bothered to check it out.

[#4]

I've checked your billing and can confirm that we paid for your line activation and router when you signed up, on the basis that you stay with us for 12 months. As you're leaving after six, we need to reclaim those charges, along with the cessation fee as you've chosen to cancel entirely, as opposed to requesting a MAC key.
If you have statements showing that we have charged you for these amounts at another time then we will have no hesitation in refunding you.