Vodacom Customer Service is BAD

I called Vodacom and spoke to Megan at 2.28pm on 07/04/2016 to query why I was going to be charged R573.99 in May 2016. Indeed, I was charged this amount on 03 May 2016 when in fact I usually only pay about R325 per month for my contract. I was given a Refe No 1-2CUKXAB and was told the matter would be resolved within 7 working days. A whole month has passed and other than the 2 messages that were 07/04/2016 and the final one on 26/04/2016 I am none the wiser. The message sent on 26/04/2016 stated that the query was closed. How is this possible when the matter was not resolved to my satisfaction. I will be cancelling this contract in October 2016 when it comes to term.