Worse Customer Service - OnAir TV

On Air TV is the worse business that i have ever dealt with. I have an account with them and has never been in arrears. Last December 2020 they for some unknown reason debited my bank account on the 19th instead of the agreed date of the 20th. They contacted me and advised me to make an EFT payment to their bank account, which i did and sent them a proof of payment. They confirmed receipt of the proof of payment. To my surprise I am being harassed with phone calls, sms and emails demanding payment of the said arrears. i have explained to them and sent the proof of payment several times but still they are insisting that i still owe them. I would like to expose their behavior for others to be aware of how they treat their customers.