Vodacom can't migrate me

I bought an Apple Watch 6 cellular and wanted to subscribe to Vodacom's "One Number" Service, which is an addon service the Apple Watch for R25 pm. For some inexplicable reason, the service is only available on Open Contract. So despite me having a very expensive, but Top Up Vodacom contract, I was not eligible for the One Number service. (Is there any good reason why Top Up don't qualify?). Anyway, I tried to migrate my contract to an open contract. Despite spending hours on the line with a number of consultants, they STILL CANT MIGRATE MY CONTRACT TO AN OPEN CONTRACT. It has been two months now. Why can't Vodacom get this right? I might as well have bought the normal Apple Watch 6! Can you migrate me please!!!