No way forward

Good Day

I have 3 contracts with MTN and on the *** im unable to upgrade and on the app it say I can upgrade on the 13/12/2023 and the call centre says its an early upgrade which is not stated and now I want to upgrade I can and the payment cant be split into 3 months and the departments keep transferring me and they say they will send SMS which they do .

Please assist on what I must do next?

Regards Kamogelo