The Minnesota Better Business Bureau is warning residents about a new take on an old phone scam. The scammers use a computer to call random cell phones with what looks like a 473 area code – and then hang up after one ring. Officials warn that 473 is an international area code for Granada, and if you call the number back you can very quickly ring up some big bills. The typical charges are $20 right of the bat for the international call, and then $9 per-minute after that. Other international area codes are sometimes used as well. The scam is a new version of “ring and run” frauds in which 3rd-parties use a tactic called “cramming” to add unauthorized or deceptive charges to your bill without your knowledge. Officials say that the best way to beat this scam is to not answer unknown numbers, and don’t call them back.