airtime just disappear

i have been loosing my airtime for past two months and when i call to query the matter am told that i have made a call and the number has only five digits. i am surprised that the system doesn't update that i loaded airtime but it has a record of me making a call that i don't even remember and my phone log doesn't have the number. i tried to query the matter the consultant told me rudely so that she is telling me and that''s what the system says so i have just to believe that i made a call that took my airtime that i don't even remember making. i am tired of this network and people should be careful with their airtime because MTN is on the business of taking our airtime to cover for wages of their striking employees. this is bad business. another surprising thing is that i am told i had 22 rand after the call but i wake up with my airtime at 25 and it is bizarre cause the system doesn't know where that airtime of 3 extra comes from and now the consultants says i didn't switch off my data but my data is off.