MTN IS UNABLE TO PROVIDE ARCHIVED INVOICES

I have a cellphone contract this company. Before I was able to directly download my invoices on their website and submit to the company for refund. Suddenly everything stopped and I didn't mind. Since January 2021 I'm trying to get my invoices from July to October 2020 but there is no one able to provide them. Since January I'm being having endless calls with them to get them but no luck. They keep on sending me from one email to another one. I even went to their offices to request for those invoices but still no luck. Finally one agent felt so bad and decided to disclose to me the real reason I can't get those invoices; it appears that their technology team was so intelligent enough that they decided to migrate their database to another system with preserving the archives. That's so brilliant isn't it? Where the hell in this century a telco company like MTN can migrate their system without migrating the existing databases? How do we call that type of technology? Is it a new discovery? I don't know. From where I'm sitting right now my company cannot refund me for those expenses because no invoices as proof. This is about R2,300 x 4 = R9,200. What a lost. We this frustration I asked them to end my contract but they claim to charge me for that. I had 3 contracts with them, 2 expired already and I didn't renew, so I asked them to terminate the only remaining one due to their poor level of services, but they want to charge me for early termination. They behave just like they can do whatever they want to us consumers. But I'm still in shock with that methodology to migrate systems without preserving the customer's data. Super good. And this is a telco company. Even a tuck shop wouldn't do that. For 3 months now that I'm trying to get my invoices.