Guard Risk debits without my consent

Totally upset at why Financial Services continuously without keep using this insurance company for underwriting.

On the 6th of December 2019 I spoke to a lady and cancelled my cellphone insurance which I have with MTN. I got a SMS stating that it has been cancelled however on the 27th of December 2019 when money was deducted, the stupid insurance was included. What the hell? That lady confirmed it was cancelled. You guys need to do something, hire staff that is ready not to lose their jobs over deducting money without my consent and reverse my money or close this company. It’s utter nonsense. Do you guys even notice how many people complain about your service??? I’m super furious.