Overcharging for promotional data bundle

My 24 month contract recently expired and I am now being charged for the promotional 5GB bundle which I never consented to. Lodged a case under case number ***5 however no feedback as yet. <br> The call centre agents, team leaders and managers are extremely useless and *********** ....the more of them you speak to the more confused you get....the billing system is just as confusing (even the call centre agents were confused).....pathetic service.....