Poor customer service

If it was possible to give 0 stars I would. I am so frustrated with Vodacom. I wanted to confirm a simple thing and that is: where did my airtime go. Firstly the app lets you chat with Tobi the robot which is useless because he can't show you where the airtime went. Then I phoned the call centre and the asked me a bunch of questions which a answered including my ID nr and bank and type of account etc. after which they asked me for my contract number which I don't know from the top of my head and to top it off the invoice is on the phone that I am phoning from. The lady says she can't help me if I don't have 2 answers correct even though I had all 3 answers correct. It is a waste of time to try and ask a simple question: where did my airtime go??? If I get 175 airtime per month and yesterday was the 1st and I still have airtime that carried over from the previous month, how is it possible to have 156 airtime on the 1st??? I am sick and tired of always having to complain on hello peter if I want to get something resolved.