Increase of Contract Fees -Disgraceful Vodacom

I have received an SMS from Vodacom that my Smart XL subscription is going to increase on the 1st May 2105 from R699 to R739. I signed a 24 month contract for R699, how can you put it up. Plus the coverage at my office and my home is absolutely ******* so not even getting a good service. Really happy that my contract is expiring in June and I will get the option to look around for a better deal. I have been a customer for twenty years and definitely don't deserve this.