So frustated With Cell C

I was a loyal Cell C customer until my airtime disappeared a month ago, I phoned customer services and the referred me to the technical department , a day later I was credited with 16 rand a quarter of my disappeared airtime. On Sunday the 12th of July, I loaded 20 rand and made one call, then the next thing I had no airtime, I bought more for 25 rand and loaded again same thing happened, I borrowed emergency airtime and all of it was gone. I phoned customer services and spoke to a Zinhle and she could help instead accused me of spending my airtime on the internet. My Safari is off on my Iphone so how do I get on the internet. I need my airtime back and Cell C must employ new customer focused people who solve problems not accuse customers of lying. if they could fix the problem before and refund my airtime why cant they do the same now.