Upgrade complaint

I app**** for an contract upgrade which included a Samsung cellphone at the beginning of October 2019 on the 11th of October 2019 I received an sms that stated my application was approved and upgraded. To date I have not received the cellphone. I emailed queries on the 2nd, 3rd, 13th, 18th and 22nd of December 2019 to which the only response that I received was a request for my account details which I provided every time I even sent through my account statement. Since October my monthly account was increased and payed, but I never received the upgraded handset. In the meantime MTN demanded the full increased monthly payment and could not let me know why I have not received my new handset. I would appreciate if this unpleasant situation could be resolved as soon as possible. Ps: This is my secondary phone which is used by my fiance Ms S. Loock