Telkom is useless with bad customer service

I cancelled a product with telkom on the 5th December 2017, they didn't cancel I called and spoke to Lungile Magazi on the 5th January 2018 she asked me to send the email with cancellation form to her and I did, she didn't cancel the product AGAIN then called on the 31st January 2018 I spoke to Nontobeko Ngubane and even her also she didn't cancel until I spoke to the last guy who cancelled the product , but Telkom is still debiting my bank account and they debited R789.15 again yesterday 15th March 2018 when I try to call them today 16th March 2018 they don't pick up. I have reversed February debit they did.