Bad service after upgrading

I have never seen such a bad service as what I got when I recently upgraded with Cell C. I upgraded in November at Cell C Campus square to Pinnacle 100 with Huawei P10 lite and there was a 10 Gig once off data which was supposed to come with the contract. I never got that 10 Gig and I called the call centre and spoke to more than 10 consultants and no one could assist. I had to go back to the shop at Campus Square and the guy who assisted me told me that there was a mistake on the adverti*****t. Which means that Cell C was doing false adverti*****t. No one has been able to explain what happened to the 10 Gig which was supposed to be allocated to me. This is just bad service for such a big company.