Cancelled contract in 2012 not yet resolved

I cancelled 2 contracts on the 17/07/12 at 9h02am via email to [Email Removed] This is a month before my contracts expired on the 14/08/12. I received an email confirmation on the 24/07/12 from Thato Moghobu.After that deductions were still going off my account in September and October 2012. When i called in to the call centre, i was told my contract had been extended to the 31/10/12 without my consent. I had reversed the ******* deductions from my account and now 3 years later for the first time i have received a lawyers letter for the amount of R607.10, dated the 07/10/15. I do not owe any money to cell c as my last debit order went off on the 25/09/12 for the month of August. i have tried to call Mershall and emailed her but have not received a reply yet. I am disgusted that i have received a lawyers letter 3 years later for non payment which is not correct.