Telkom' s bad client service

After numerous efforts to cancel my cell phone contract with Telkom , which ended in March 2015, I am still being debited every month with a sudden increased amount which can't be explained by their accounts staff. Telkom's personnel at Clearwater Mall are very helpful but are as perplexed as myself as to why the cancellation won't be accepted by their mobile division. Getting rude calls from a '' lady'' Neo telling me I shall pay or else..! They have given me over to a debt collection company, Nu Debt Management ( Done Anderson ) for an amount of R 270.00. I have all the necessary ref numbers which was given to me when I cancelled the contract but their client retention division seems to ignore it. Telkom's staff at Clearwater Mall are feeling helpless because not even they can get any reaction from Telkom's accounts dept or an explanation on the increased instalments, or lack of want to cancel the contract. I have now paid the amount, but am still in the dark whether they are going to continue debiting my account regardless the fact that I have cancelled the contract months ago. How am I going to get my money back that I was forced to pay. Names and reference no's are available.