Falls advertising on promotion

I am disappointed with this company. My issue is that they sent a promotion I'm April 2021 for customer to upgrade for 2 months to premium package and will be charged R599 but to my amazement I have been charged total premium amount and none of their agents are not aware of this promotion as I asked. Thus this indicates lack of internal company communications or it falls advertising so that they may increase revenue. I am writing this still holing on to speak tothe supervisor it's benn 30 minutes been put on hold. I wand to be refunded the difference of amount charged. This is the worst service ever. On Saturday I spoke to Aviwe and he promised thay the problem will be resolved before debit order goes through no resolution to this day.