Telkom Mobile please close my contract.

I had (actually have) a mobile contract with Telkom. I was told my the store & call center agents I would need to submit a document to a cancellations email address with a scanned & signed document 30 days in advance. I made sure I got all the information as I have had issues previously with the landline phone number. My contract was due for expiry on the 01 May 2018, I submitted these documents on the 31st March 2018 (30 days in advance rule). I received a call from the lady (from Telkom cancellations) who reassured me that my contract is cancelled & no offer and/or payment will go off in the month after June. On the 1st of June, I found that they had debited a R150 less from my original contract balance. I was okay with this as it was the last month, only to find the following week that the contact agents were asking me about the renewal, after the 5th or 6th call, I then asked why is it they call when I have made arrangements to have this contract cancelled, to be told that I didn't cancel my contract. I do not understand the miscommunication - it has been 3 months of debits for products I didn't ask for. Why won't you close/cancel my account Telkom Mobile?