Expired Contract Cancellation

My Vodacom contract expired on the 1st of February 2022. I have phoned in for cancellation and I was told there will be a last debit order on the 20th of February. Surprisingly I was credited with airtime and I have phoned in to follow up and the consultant assured me that he will get the March invoice to be credited because it was an error from their side. He then suggested a cheaper package for upgrade which he offered a total 15 gig monthly, 5 gig night, 5 anytime and 5 gig streaming. This package cost R79 per month. I have received and invoice for R175 to be debit 20th March then I have phoned in on the 11th March for cancellation because this is not what I have agreed on. I was told again that the cancellation will be done. On the 15th I have phoned again and told I have recently upgraded I cannot cancel and the consultant again said the consultant who assisted me with cancellation will contact me before end of day but it did not happen.