Next Directory Unenforceable Credit Act?

[Chocotabbie]

Dear All, I purchased some items on line back in 2010 with the Next Directory, I paid and they arrived. They then gave me a value I could purchase items too, again i did and paid. Now this has been going back and forth ever since and I now have a bill for 900.00 I have fallen into difficulties so i asked if i could reduce my monthly payments. They then asked me to sign a credit agreement as they didn't have one for me. I don't want to sign and this set alarm bells ringing. They haven't physically sent me the ca yet, but i have googled their rates and interest etc and it looks like i have paid for my items at least twice over the years! Can i refuse the agreement and say that I am not paying the rates as I have never agreed, therefore account will be closed as I have more than paid for the goods? I have also asked for copy statements of everything as I cannot retrieve any from online as I want to see exactly what I have spent and what I have paid. All suggestions welcome. Kindest.