needed assistance with a billing query

I needed to speak to a Mtn agent as I was informed via Sm's that if I used R9 worth of airtime I would be rewarded with an amount of R70 worth of airtime, So I used R10 worth of airtime and wasn't given anything back I still needed to use R4.58 to receive the R70, so I then tried calling 173 as they are pre paid help line, so I was then told via 173 that I've exceeded my limit in regards to calls to customer service, so I then called 808 because they where the only people that I could get through to and I explained to Thembisela Nkosi that I wasn't getting through to 173 and she kept insisting that I must keep trying instead of helping me as she represents Mtn although she is in the contract department I'm sure she would have some knowledge as to my compliant, so I asked to speak to her Manager and she refused as I was told the manager( Sam Mdunge) were in A meeting, so I felt that being a prepaid client I wasn't not treated as a valued client as to contract customers.... I believe that this is totally ridculous and there are incompitant agents being employed by Mtn....Clients are treated as just a number and a few agents give other agents a bad name.