New contract and not upgrade

I app**** for a black friday new contract data router. R299 for 100gig. But then mtn online upgraded my main account cellphone line to the data only router. I am a hospital pharmacist and on call 24/7. My cellphone is now a data router seeing I received no simcard with my new router application. I have spoken to 7 different operators and no one is able to change the data router to a new contract and leave my existing cellphone number as is on current contract. And just send me a new simcard to fit the Huawei mobile wifi router.