Billing ****

Vodacom is an unfair institution. according to me, my contract was suppose to expire in June. this contract had at discounted price. In June 2018 i received a bill indicating double the price. when i called them i was told the discount ended in march. how was I suppose to know if i was not informed? Yet my bill for April and May was billed at the discounted amount. I queried the bill and was told it will be sorted. To my surprise i still got debited the double amount, when i called them to check what happened, now all of a sudden the agent tells me the discount ended in May. I want my money back Vodacom.