Data & Airtime Taken from my account

I loaded R160 data equals 1G 2 days ago. Also loaded R180 airtime. I haven't used either a lot and I receive a message saying my data is finished. I then type *141# and the info gives me incorrect figures every time I key inn. First key inn gives me R129 airtime key inn the second it drops to R87 and I didn't even make a call. Mtn has been *****ing from our accounts. I'd like a full explanation and more than adequate reimbur*****t for this misrepresentation! Where did my airtime and data disappear to?