It costs them to "process" your card every month, send you a statement saying you don't owe them anything, etc. is probably why you got dropped. You cost them money if you weren't using the card at all.

Why do you have so many? We have the two; the one my husband uses predominantly and the one I use. We have the two so if we have a problem with the one (lost, stolen, etc.) then we have the other. I carry both with me but my husband only carries his one (that way I can put things on "his" card so mine won't look like I've spent as much, LOL). But when we were down in Florida a couple years ago we were shopping, bought some expensive items in a couple stores and since we were away from home, they put a freeze on my husband's card so we had to use mine until we could call them and find out what was happening and get the freeze lifted. They're both from the same bank though so that was amusing; left hand not knowing what the right hand is doing?

We actually had AT&T try to charge us for not making any long distance calls on our business phone. Guess who got dropped as our long distance carrier on that phone?