Extremely poor service

Yes I agree, my debit order returned and as soon as I received a notification I made an immediate payment that was on friday 05 January 2023, I sent them a proof of payment via whatsapp and email as per the message I received. Tried calling them countless times with no answer. I resent countless whatsapp messages as I use this phone for work, no one answers and the phone rings, no one replies to my whatsapp or emails. I do not know what to do anymore as I use this phone to work.