Cancelled contract

I've called in numeral times regarding the cancelation of my contract that's suppose to expire end of February 2016,i phoned in beginning of January to cancel my contract and give my 30days notice, I then requested for n cancellation letter, I also arranged that my last debit order should be END of January 2016. On the 16th of January they debited my account, I've phoned in and explained the problem only to find out that by contract was never cancelled like requested and my debit order was never updated like requested. Because it was over the weekend the guy that I spoke to said that he would handle the case and let one of the managers phone me to sort this out! TILL TODAY I HAVENT RECIEVED ANY PHONE CALL!! I phoned in today only to be notified that my account is in arrears, and that they wanted to hand me over. I feel this is unacceptable because now I have to pay extra fees because of someone that didn't do their jobs properly! I'm really disappointed in the manner that they treated me. I feel sorry for their remaining customers.