If you are a US citizen, be very careful when you are required to call certain numbers, in order to complete a deal, transaction, or redeem a prize.
As close as these might sound to US area codes, numbers like 809, 876, or 284 are actually Caribbean. The whole scam is to keep you on the line for a few minutes, while they are collecting their money.
How to avoid: always research the Internet for the area codes and the name of the company you are calling.