MTN contract on wrong cellphone number

I am a very dissapointed and hurt MTN customer. My family is MTN clients since 2003. I personally had a MTN contract since 2013. In 2017 Summer Mobile contacted on behalf of MTN for a offer which I accpeted. I never received my simcard and paid the 2 year contract. I visited MTN several times, they attempted 2 sim swops which I paid fot and it was unsucessful as i still didnt receive the data package. MTN stated that they cannot close the contract or assist me because Summer mobile is a outside contract. I didnt understand it as the installment was combined, however I accepted it and paid 2 years for the contract. SECONDLY, when that contract expired, I UPGRADED my contract at MTN 17 June/July 2021. The installment is over the R600 montly. I realised that i dont receive my airtime package. I contacted the MTN branch and they said it will be loaded the 12th. Note that it is an enitre month after i took the contract. So i waited until the 12th. It again wasnt loaded, i visited the branch on 3 occasions and called the call centre twice. Eventually they figured out that Summer mobile probably cancelled the incorrect phone number and that my MTN contract is now on a different number. NOW MTN cannot assist me. They state my only choice is to change my phone number to the new number, which i REFUSE TO DO, asI had this phone number since 2003. so again, i am paying a contract that i do not receive my data and airtime for which i have to buy separately as Pay as you Go. Can some PLEASE assist me with this issue. Thank you in advance.