Credit Intel harassing people for their fees! Not their client

Terrible debt collector! I paid my final account to Impact Meters in November 2020 but was handed me over to Credit Intel. Since then until now Credit Intel charges me interest and fees monthly for their sms, cost and emails for 7 months even though their client Impact Meters was already paid in full. They reply that they charge according to the law and its legal for them to charge me fees that will continue to go up because we where handed over and need to pay their fees.I reported them to the debt collectors Ombudsman who reply with a snipit of the debt collectors fee structure.Is this the disgraceful law in S.A that we forced to pay increasing debt collectors fees?!!!