I'm not disagreeing with respect to Parallels, but there's no need to be rude to them, no matter what. He could have expressed his anger without being rude. To be frank, he comes off like a petulant child. And where did it get him? Put yourself in their shoes, would they rather please a customer who is being calm and logical, or one who is insulting them? Just tell them you are not happy with their service and will be planning to switch to one of the alternatives; no nastiness necessary.