Whatchamacallit

Error in removing bulky security tag
I am a grandmother that purchased her grand daughter a prom dress that cost almost $900. Day of prom we had hair done, makeup and photographer was at home to have pictures before leaving. Two other couples already arrived . Ten min before going outside to take pictures and leave she puts dress on. To our surprise the bulky security tag is on. I call store to ask if I could cut off and they said ink my come out. This is a white dress. She then said come back another day and she can have free earrings or shoes. She really didn't care. I was so upset and we couldn't go to store as we live an hour away. I called again after prom was over because grand daughter didn't get to wear dress the entire time because tag was scratching her and was told they could give us $75 but that was it because prom was over.I wanted owner to call us. She still hasn't called