Mtn isn't fair

I'm so disappointed with how mtn dealt with my situation. My partner took contracts phone on behalf of the two of us..... I'm supposed to be receiving R230 worth of airtime everymonth. on the 1st of January I got my R230 as well as 5gb (which I thought was promotional data since we are new on the contract so I didn't question that).... A couple of hours later both the airtime and data had vanished I called the mtn call center and evertime I was given a story, until yesterday I got a lady who assisted me so well 😊... She Than explained to me that all she could see was that I had used my airtime as data, which is highly impossible because my setting for out of data settings are off..... I feel like mtn did a munber on me really I just lost airtime and 5 gb just like that and I'm supposed to be OK with a lousy explaination 🤔.....