Poor After-Sales Service - Cell C

I contacted Cell C on 27 September 2018 to do an upgrade. I chose my desired contract which included Talk Minutes, SMS', Data and Black Data. When my allocation was given to me for the month commencing 1 Oct 2018, I noticed on the app that there was no Black Data allocated. I called the contact centre, the agent reviewed the telephonic conversation and confirmed that indeed it (Black Data) was discussed with me. I received a reference number and was informed that someone would contact me. I received a call from someone after making a follow up call and he informed me that I would receive a voucher (3 month's worth) for Black data that I would have to follow a series of steps to activate and thereafter I would be allocated Black Data (as per my other allocations) each month for the duration of my contract. No voucher has been received since. I have called and an agent assisted me by notifying the gentleman who assisted me, to contact me and do as promised. I have not received the data and no one seems to be interested in my claim/issue/requirements. I had to speak to 3 different departments on one particular day and no one helped to resolve my query. Shoddy service indeed, however they are extremely efficient and responsive when signing you up!!!!