Shocking Customer Service from Call Centre Agents

Since May 2015 I am trying to resolve matter where Adhoc data bundles of 5 GIGS were purchased via my account pro online, sms received confirming data been loaded, and still charge data charges at month end, however am not billed monthly for these 5 GIGS. Logged call in May, was told to wait 5-7days someone will get back to me, called in 16th June only to find out previous consultant I spoke to did not log my complaint so I had to start all over again explaining and eventually call logged again with reference number 729668 with Pretty, again told to expect response 5-7 working days, again nothing happened no one call, so I called in again, spoke to another consultant (male) advised me nothing has been done, so he will help me, made me hold on for about 15mins whilst he contacted service provider MTN, MTN advised that I have data for about 18gigs in credit on my profile and they cannot understand why its not been allocated to my number, so he will log a query for them to look into this and to refund me the charges to my current account. Again no one called me, I now want to speak to a manager to discuss further as the story goes on, new ref. number 784727 logged again yesterday.