Cell C told me to cancel with Rain and then doesn't reneged on 'confirmed' offer

On the 1st we called in enquiring about cell c Fibre, none available. The agent offered an upgrade to current LTE package. Confirmed thatvwe qualified and that I should go ahead and cancel product that I had with another company. Calls me back at the end of the day and says that it can't be done. I had already burnt my bridged with the company by then. I had been receiving 30g day and 30g night on my initial cell c Co tract... On checking my contract again.... They had reduced it to 5g day and 5g night! Called then transferred me to upgrades.. There was no answer. Whole of Friday. In the late afternoon, upgrades called and apologized and then offered me 30g day and 20gb note plus a further 20g nite as an apology. For which I would pay almost the same price. To date I have not received the extra. To date, I have not yet received the extra night data as promised.. The lady from retentions had refused to call me back, despite numerous messages requesting her to do so. I simply cannot believe that the Stagg is so busy that they cannot call to update. I have asked to speak with a manager but there is NEVER nib available... Across the entire company. This is appalling service from Cell C!