I recall I bought some goods of one site and the terms on their website were if you attempt a chargeback they will give you a bad crediit rating. is this for real?
No. More likely it was an illicit website. Your credit rating is not determined by how many times you get ripped off by scrupulous merchants. Your credit rating (at least in Denmark) is determined by things like salary, property ownership, car ownership, telephone ownership, and paying bills on time (or at least, not losing in court over it). Just go get 'em Rob! Feed them to the lions!