If I used sick time to cover being out,can they take vacation time away also?

I was out sick and used my earned sick time to cover the week I was wrote out of work for a torn tendon. When I came back I was told that I was losing 8 hours of vacation time along with the 40 hours of sick I used because I wasn't here to accrue the vacation time. I have never had this happen before,as long as I had sick time to cover me. Would the sick time not also count as worked time since I did work to accrue the sick time at some point? It seems the company is punishing you for being sick, should we not have something stating you must work x number of hours to receive x number of vacation hours and sick time does not count toward such worked hours? Any help is much appreciated since my company can not seem to figure out how many hours you need to work to get vacation hours promised.