35 minutes disappear without warning

Gooday, last Wed the 4th of July I reported that my airtime was showing 35 minutes available but when I called on the phone the voice prompt said I had 1 min left... The mtn voice operator said that I still had 35 minutes available.

Sat the 7th July I made a local call to Game stores in Bayside mall cape town & the call cut within a minute telling me 35 minutes has just disappeared in that minute.

I called MTN immediately & was told it would be resolved within a few hours...

It's now Monday the 9th July & nothing has been done forcing me to keep buying etc airtime.

SD PULLIAH ********** 010