Adt Security
ADT billing for amount already paid

Last year I had a alarm fixed at my property, and I paid by EFT transfer. This was in December.
Starting January I kept receiving bills for this amount. I have sent ADT various times the proof of payment.
Recently a lady by the surname of Mathebula phoned me to request the proof of payment, which I sent to [Email Removed]

Today I was sent an SMS telling me this amount I have already paid will be deducted by debit order the end of the month. I am not getting any assistance in this regard, and it has been eight months now. Can someone please help me!