Netstar harassments

Consistently harassed by both Netstar and a debt collection agency which they gave my confidential information to on a closed account (POPIA infringement - don't think they even know what this means). Proof of closure, certificates validating closure and email confirming payments are up to date sent via email, calls made - nothing helps. Shocking customer service - took me 6 months of payments, correspondence and a face to face visit to Netstar Midrand to close an account in last year for a vehicle I had sold! Seems like no inter-division internal communication exists and business processes seriously lacking!