Impossible to terminate contract

On Wednesday, 31 October 2018, I requested Vodacom to terminate my month-to-month contract and transfer my line to prepaid. Vodacom erroneously suspended my line and did not process the transfer to prepaid. My account has never been in arrears and therefore there is no basis for such suspension. For the past week, I've been in daily contact with Vodacom (customer care, accounts and terminations department) and they seemingly can't resolve my suspended line. It has now been a week that I've been cut off from the network and I am no closer to resolving the issue. Every day Vodacom just promises that my line will be reinstated within 24 hours... but nothing!