Refusal to assist with cancellation

1.My contract with MTN expired in June 2015. 2.Went to Menlyn branch to cancel my contract 27 June 2015. I was told that it will be cancelled the following Monday and that one last debit order will go off. My airtime and data balance changed to R0 by MTN the Monday, but contract was not cancelled. Had to spend extra money to load airtime/data for the month. 3.Back to Menlyn again to attempt cancellation for the second time after my port to Vodacom was once again unsuccessful, 30 July 2015. The exact same paperwork I filled out the 27th of June was given to me with a reference number and told it will be cancelled the next day. My airtime was changed to R0 again. 4. Tried to contact call centre with reference number to confirm cancellation on Friday 31 July, but no one answers. I tried to log in on my MTN account, but my log in details was no longer valid. 5.In order to confirm the contract was cancelled, I went to MTN Menlyn again to confirm cancellation. I was told that it wasn't done and there is yet another last debit outstanding. I asked to settle it there and then, but was informed that their payment portals do not work. 6.The last invoices/statements from MTN was April 2015.