F&$)$&king me from behind

Bathong… MTN is a ****, my airtime has being depleting and @ first I was told that it depleted from data when I have never deactivated any barring that when my data depletes it must run off my airtime and 30th dec 23 the same day I then bought 60min for an hour, I made 2 phone calls to the same number 15min and 6min both calls put together didn’t amount to 60min. I only realised after making the 2rd call that it had been depleting from my actual airtime. I case was logged and I am told that these 2 calls I made ran up to 25min, how when my call log shows the time? It’s said because MTN can say what they want to say without them asking for proof from the customer or them providing evidence of what they saying. It’s sad that i trusted this service provider that being why I chose them as my service provider and today they f@$@king me from behind