Exceedingly Poor Service!

I travelled out of the country and called to activate international roaming before I left. I am on a contract with limited airtime and data. Upon my return, I was charged roughly R700 more on my bill (July 2022 statement) for roaming charges while I still had sufficient airtime minutes. I called about 6 times to resolve this. On 2 occasions the call got cut after explaining my whole story and the other 4 occasions either the system was down or the IVR was not working properly so I could not get help. I believe the charges are incorrect and I want a full refund of the money that was debited erroneously. The conditions that were explained by the second consultabt before the call got cut makes absolutely no sense. The MTN service experience is exceedingly poor.