Vodacom - overcharging accounts due to incorrect duplicated upgrade

Vodacom East Rand Mall upgraded one of my contracts incorrectly and wrongly put the upgraded mobile device and contract onto one of my other Vodacom contracts. When this was discovered I went back to the store and it took approx. 3 months to finally correct the upgrade onto the correct Vodacom contract. UNFORTUNATELY they have still not rectified the other account back to its original contract and I have now been paying for a new device on 2 contracts instead of only 1. On the system Vodacom can see that both contracts have the same new mobile device (same IMEI number) registered against them but no one is helping to sort it out. Visits to the store, unanswered phone messages to the store manager, calls to Vodacom call center and no one is helping to sort this out but every month since the contract upgrade was done in Oct/Nov 2019, Vodacom continue to overcharge me for two new cell phones, as well as the incorrect contract amount on the contract that was not reinstated to what it was before the error they made. STOP *****ING MY MONEY EVERY MONTH AND SORT THIS OUT! Why should I have to go into the store all the time, I can only go on weekends but the manager doesn't work on weekends and he also never returns my phone calls. My debit order goes off every month without fail - you get your money so YOU DON'T CARE. I want the overcharges refunded. I want the contract that was incorrectly upgraded put back to how it should be and I WANT IT DONE NOW.