Contract arrears

Absolutely shocking service.. I signed up for a contract last week (30 August) again as I haven't been a member for 18months or so. They're very happy to sign you up and take your money and start debiting my account, then you find out that a contract is in default from 2008 that you didnt even sign financial surity for, and its from before you even started working, now they want to blacklist you for a contract that you didn't even sign. Absolutely disgusting... Where was this problem when I signed up with you in 2010 and had a fully paid contract for 5-6 years. The contract in 2008 was not signed by me!!!! Why am I now financially responsible for it?!! And if so why was I not made aware of this when I wanted to rejoin last week. This is shocking service and I will endeavour to not let other people fall into this trap of your incompetence.