Handed over

I received an sms from credit works who say i owe escape 900. The contract i took out with them was simple. Pay upfront and have 12 months. So i did. Bare in mind this was 2010 it is now 2015. Without no formal notification they handed me over. I called them and they say i paid 300. Now under their own terms how can this be possible. This is *****. I am still waiting for the lady to call me back. Who promise 15 mins. It has now been 2 hours. Absolutely pathetic. Now im not sure how long must wait. People please choose wisely people. Although they cheap look at the **** thats going on.