Cancelled Contract

In 2013 I contacted the academy and requested to cancel my contract, the irony is It took a report on Hello peter for my complaint to be attended to. Much like now again. In Feb 2013 I was eventually contacted, given an amount to pay in and a reference numer to quote and was advised to fax the proof of payment, which I did. It was then confirmed that my account was settled and the debit order cancelled and case closed, or so i though. To my disgust, fastforward 2 years later, I woke up to a call @ 6:15 am on tuesday the 28th July 2015,a consultant telling me that I owed Academy for Maths money and I must make payment arrangements. I explained to the lady that I settled my account to years prior and she asked me for the deposit slip as proof of payment. I dont have it no Two years later, then only you wake up? why was I not asked 3 months after? What was the point of making the payment and faxing the proof if you were just going to lose and blame me for it? I did my part. please go and check your bank statement and find my payment. It does not work like this! Someone did not do their job and now this is my problem. Please trace my hard earned money and do what I requested with it!