Nudebt disaster and disgrace!

Nudebt handles Telkom debts. My debt was paid by EFT in April ‘23. After that the debt was transferred to another debt consultant who transferred the account back to Nudebt on receiving the info of the April payment. Since then they keep on harassing me - though I have sent then the bank’s proof of payment. They do not even respond regarding the (lack of) allocation of the April payment. This is an irritating disaster!!!