False blacklisting. Zero detail available.

My 3+ year old phone is blocked on all networks. Apparently Vodacom blacklisted it incorrectly. I'm a MTN customer. I've logged a request here last week, after trying to resolve false blacklisting in person at Vodacom shop without any success.

Instead of rectifying the problem they caused, Vodacom called me at 16:50 on Friday to say I should contact their accounts department, which is closed on weekends... My query is related to the fact that I'm not a Vodacom customer and I've not had an account with Vodacom since 2017, yet they've erroneously blacklisted my device for bad debt. They cannot provide any detail on said bad debt, since it's clearly an error and doesn't exist. This cannot be considered helpful or described as an acceptable response to my query...

Is there anyone at Vodacom who can rectify this?