Not getting what I signed up for

I took out one of the 50Gb Black Friday specials at the end of November last year. Today is the 10th of January and I still cannot use the product that I have already paid for. As I have mentioned, I bought a 50Gb bundle. Firstly, it took almost one month to use it as the service was not properly activated and a issue arose with the assigned number. The first time I could use it, was on the 29th of December. So on the 1st of January, a new month, I use the SIM card and get a message that same afternoon that my 10Gb bundle has been depleted. As mentioned, I purchased a 50Gb bundle, not a 10Gb. The issue was logged again, and 10 days later, still not resolved, even though the full amount has been taken off my account.

What will it take for MTN to actually fix this issue? It is definitely not the shops fault as Wessel has been more that helpful and I believe went out of his way to address this. However, MTN is not doing their bit. I am at the point where I just want to cancel this contract.