I fell for it. The lure of a 20 percent discount on the spot and the promise of more coupons in my mailbox convinced me to open a Macy’s credit card even though I knew better. What I didn’t know is that I was opening two credit cards in one.

My new credit card is used as a Macy’s card when I shop at the department store. But it can also be used as a Visa card anywhere else.

How did I find this out? I paid my bill online, only to get a paper bill saying I hadn’t paid. I was charged a late fee and an exorbitant interest rate on the “unpaid” balance.

 When I called Macy’s, the customer service guy said I paid the Visa bill, but not the Macy’s. Can we say, confusion? I didn’t even know I had a Visa bill. And with a very high limit too.

The guy transferred my payment to the Macy’s bill. But I have to say I’m still a little peeved. Like a lot of people, I’m not using much credit these days. And I definitely don’t want that much open credit.

It just reminded me to be very, very careful with credit cards. Credit card companies are raising interest rates and cutting limits as they prepare for more stringent rules to take effect in February. Banks also say they are seeing higher default rates because of the economy. Read what my colleague Eileen Ambrose recently wrote about one man’s experience. 

Here are tips from Consumers Union about credit card traps to avoid.

(Photo courtesy of AP)