Don't trust any exchanger website, especially if they offer paypal as payment, you know they are scammers right away. Search the phone number on the site they have on it. See  what country the area code is from, I would only do business with companies that are local to me, meaning in the same country or atleast in the same continent.
Do a search most of all, it is a simple thing to do even if you are in a rush, type scam after your search to reveal any suspicion on them or any activity they are done in the past to victim's of their schemes.
Your credit card company should be able to do a reverse on a fraudulent charge if your credit card has insurance on it that you are paying for or is included with your particular card plan benefits. But this can take up to 30 days for them to do an investigation and they would need proof sent to them like screenshots and chat logs of the transaction(s) that are in question. If it is a prepaid credit card you are talking about, then you aren't able to do anything about it and you have lost your money, end of story.