Can't keep number because I want to stay with FNB connect

So I had an FNB connect package, was really happy with my package had it for the full 24 months, then when I decided to buy a new phone and package I requested on the online application to keep my own number. This did not happen and I received a new Sim with a new number. I proceeded to call the help center and ask if it was possible to do a Sim swap or something so that my new contract has my number. The consultant then told me that it's not possible because my previous phone number was also with FNB so because I chose to stay with the FNB connect product I can't keep my phone number. I find that rediculous, that makes it impossible to upgrade your phone through their service. With many of the other companies you are able to change your package and keep your phone number even if your pervious package is with the same provider. Very disappointed.