Stupid MTN

Very very angry now, so I paid my contract phone on Friday 29th January 2021 via eft and I got my data & airtime etc, they even sent me a confirmation message then boom Monday 01 February 2021 they decided to deduct double my monthly payment. Now I have to reverse the debit order and get charged still by my bank. Guys you need to pay back my money I've already paid you.