There charging me all sorts letters are 12 pound late payment, I'm arguing with them and I've stopped paying about this, and the unsigned credit agreement, the account was opened in 2010 can I still claim back the fees?

I did purchase some items from jacamo there was no tick box on the site, I asked them for a copy of my credit agreement they said I had signed, they sent me a blank one. So I made a arrangement to pay them in instalments and I was paying 50 pound a month but after 3 months I noticed they where still applying interest on the account which was higher than the payments, on there letters they said they would freeze all interest, when i questioned this they told me they don't freeze it right only if they deem it to be the right choice, now I'm in a rut and its getting worse, I don't know where to turn Sorry about grammar I'm on my phone and can't see much on the screen

Hi I'm new to the forums and would really appreciate any help as I don't know what to do. I'm having problems after sending a CCA to Jacamo and Reliable Collections, they sent back an unsigned CCA, so I sent a default notice then received this letter below: Dear XXXXXXXXXXX Re: Account Number XXXXXXXXXXX Thank you for your email. We have noted your assertion that you did not sign the credit agreement in respect of the above account. In the absence of any valid dispute over the conponents that make up the balance of your account we consider your assertion that you have no legal liabillity for payment to be based purely on the fact that you claim that the relivent credit aggreement has not been signed. You should be aware of the important changes implemented by the Consumer Credit Act 2006 in respect of credit agreements entered into after April 2007. As your credit account was opened after this date, even if we are unable to produce a signed agreement (which was not admitted) we have the right to apply to the court for an enforcement order. An order will be made under the provisions of section 127 of the Consumer Credit Act 1974 (as amended by the Consumer Credit Act 2006) unless the court finds that prejudice has been caused as a result of your alleged failure to sign the agreement. We do not consider that you have been prejudiced in any way by the alleged omission of your signature on your credit agreement, and we are confident that we would be successful in any application for an enforcement order in respect of the agreement. if you continue to deny any liability in respect of your debt and fail to make any further payments towards it we can apply to the court for an enforcement order in respect of the agreement and reserve our right to seek the costs and interest. In addition, our rights in relation to pursuing you for the cash balance of the goods are fully reserved. We would therefore advise that the outstanding arrears are currently £XXX and an immediate payment is required to bring the account up to date. If you are currently experiencing financial difficulties, there are options available, which may help your situation. Where appropriate we can consider reduced repayments and/or cancelling interest charges. We await your reply. Yours sincerely