Useless *********** call centre

Useless *********** call centre I loaded airtime to convert into data. If i dial *136# it shows R50 but on *141# it shows R41. Call centre "lady" was too lazy or untrained to understand the problem and after explaining twice she demanded to know why I contacted them. She then cut me off twice. As a result I have insufficient airtime to convert and no idea where the R9 went. With a zoom meeting in an hour MTN has ruined my day.