Account settled but handed over again

Defaulted on a data contract due to unemployment.

Endless problems with collection agency. Ended up phoning Cell C direct. Got a final amount in January 2020.paid in full before end January 2020.

Send proof, email confirmed it was received and allocated. Now after 10 months this account was handed over to another agency. With two days apart the amount has changed.

I have send all paperwork and emails to new agency, but are still harassing me.

Though Vodacom was useless, but Cell C beat them by far!!