cablecard not compatible with Internet/TV bundle

A couple of days ago, I called support to get rid of TV (too expensive). The support person convinced me to get a bundle with Internet and local TV with the mini box ($2 cheaper than just Internet?!?). I'd asked if I could still use my Ceton/cablecard, she said yes. Well, my wife returned the old equipment to a Cox store and the salesperson said no, we can't use our cablecard. So, which is it? Can we or can we not? Does anybody know? Has anybody encountered this?