***********, inefficient and ridiculous

I cannot believe this company. I have cancelled my internet service late December 2020 and it required a months notice therefore it was cancelled at the end of January 2021. All that was okay, until yesterday, i receive an SMS stating that my account is in arrears, to my astonishment i am being charged for February 2021. I have attached an image showing that i requested the cancellation on the 22nd December 2020. Thereafter i received a call from the agent and accordingly the cancellation was processed. How can you charge for services not provided? I call them and on 2 different occasions i reach being caller number 1 in the queue only to get cut off after staying on hold for over an hour. I cannot believe this!!! I hope they can resolve this matter or if anyone can help me, PLEASE HELP