Vodacom data charges

Vodacom struggled over a period of 2.5 months to port me to their network. Due to the very frustrating delay they offered me an amount of courtesy data for a period of time (1GB per month for 6 months), which I was very appreciative of. Unfortunately at no point in time did they explain to me that the 'free data' offered would be on a pro rata basis for the first month due to the port only successfully going through on the 22nd of the month. Not only was the 1GB of free data promised to me reduced to +-200MB but I then also had to incur expensive data charges once the pro rata data had run out as well as an additional cost for the purchase of a top up data bundle. Very disappointing 'overpromise and under deliver' experience to date!