Dratsab: Looking at your website, yes - WxC pricing is a lot more expensive than Vodafone. However, pricing is not what the thread is about, is it?
No... it's about folk changing their mind about what ever they've made a commitment to and then blaming someone else.
It's an acceptable model, and there are lots of other acceptable ones too. It just happens that the OP has decided it doesn't suit anymore.