Double Payment

Last Month (April 2020) my Debit order didn't go through as per arrangement on the 25th, i then with immediate effect made a payment on the website and payment was sucessful. to my surprise telkom kept on on sending Threats that they will cut off my line. i then sent a message on their twitter business page explaining my frustrations. the only response i got was, "is your line suspended?" i then said no and that was it. Now Telkom have just debited me double payment this month. Telkom why??

please refund my money ASAP