You get a call from Comcast and the person on the other end says you can lock in a decent rate for the next year if you pay for the first six months’ worth of service up front. It sounds a bit odd, but you’re always looking to save a few bucks, so you keep listening. The caller then tells you that the only way to pay that money is to put it on a prepaid cash card. This is when you hang up because the caller is probably trying to run a scam on you.

KUSA-TV reports that Comcast customers in the Denver area have recently been taken in by scammers pretending to be Comcast.

The callers either have some inside info or are really good at guessing, as KUSA reports that they convince customers the call is legitimate by knowing how long the customers have had Comcast service, which packages they have, and how much they are paying each month. The information is not always entirely accurate, but it’s been sufficient to fool some customers.

What we can’t figure out is why customers don’t sniff a scam when the caller demands that the $600 up front money be paid — not in cash, check, or credit card — but with a Green Dot MoneyPak prepaid cash card. Comcast does accept these cards, but it’s never the only option. Meanwhile, the caller expects the customer to go out and purchase a card, load it up with money, and then provide the account info and PIN to the scammer.

Since that can’t obviously all be done in one call, the scammer needs to provide a call-back number. When hoodwinked customers call that number, the recorded voice states that “you have reached the Comcast Infinity rewards program.”

The scam doesn’t just steal money from Comcast customers; it can also screw up their Comcast account. See, the scam caller tells the customer that by paying the $600, they won’t have to pay anything to Comcast for the next six months.

Thus, people who don’t realize they’ve been scammed will stop paying their Comcast bills, only to find service cut off after a few months of non-payment.

In a statement to KUSA, Comcast says it is “aware of the Green Dot MoneyPak scam in which victims receive an email, or call offering them a promotional package for Comcast services.”

The cable giant confirms that it does accept Green Dot as one form of payment from customers but, “under no circumstances would it be required in advance for services.”

Comcast says customers should verify promotions by checking comcast.com or by calling 1-800-COMCAST.

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.