Miscommunication which cost me a lot

I app**** for a contract for a new Sim. Instead the consultant decided to load the data on my Sim that I am currently using ***and change my plan from prepaid to contract. I then asked for cancellation of the contract because why is my old Sim card changed to Contract while I app**** for a new sim card. I was told to decline the delivery of the new Sim card. I did that and my number is still on contract, they loaded their data today on my old Sim card. MTN internet gold. That was not the agreement. Please cancel your contract and take my old number *** back to prepaid.