Telkom thievery

I had a contract for a LTE wifi contract with Telkom for 2 years. This contract started in April 2016 and was due for upgrade in April 2018. I cancelled the contract via email as well as telephonically. The service was suspended but Telkom CONTINUED to debit my account. I went to the store to confirm cancelation and STILL, 2 years later, money is deducted from my account!!!