unjust service

I requested to do a Sim swop on a number that was registered in my sisters name, and i was told that Telkom will not be able to assist, i have stressed the fact that i have personally been using the number for 10years plus and my sister is not available in the country to go to the Telkom store, this has caused severe consequences on my end as i cannot access certain information and platforms because of the OTP, i could not stop certain subscriptions because of the OTP, even after I went with a sworn affidavit to the store no one could assist, i am very dissatisfied with your services