Well, you can try the Maxine approach. I was in the fabric department in a Texas store and rang the bell three times. Someone else came up and rang it once or twice. All in all, waited over 5 minutes. Then I used my "Mother Wants You Now" voice and yelled "Is Anybody Working Fabric". A lady popped out from another aisle and said "You didn't have to yell, ring the bell." I told her we'd already done that multiple times.
Found out it's easier to get out your cellphone, call the store and ask for the manager. When the manager gets on the line, tell them you're in fabric have been there XXX number of minutes and need someone to cut fabric. Works fairly well.