MTN don't know what they are doing

I app**** for a voice(convert pay as you go over to contract) and data sim via Rewards CO. I asked for a dual sim phone they sent me a single sim Samsung A50 with the contract. The data sim never worked even after 5 time being told it will start working within 2hrs. 7 Days later it was still not working so I handed everything back to them to get it canceled. Got a shipping nr everything. This was in September 2019. All i want is my number to be converted back to pay as you go. Every time they said it is sorted but my number still on contract. Don't know what to do anymore.