Unprofessional attitude, unethical conduct

I bought a groupon voucher in October14 for a massage at Beauty Lounge. I called several times to try secure an appointment. I was informed they are fully booked till Jan15. I then gave the voucher to my mom as a gift (it was due to expire on the 13th of Jan15). She started calling immediately to secure an apptm and i did the same on my end-from the 5th of Jan15, without any luck. I later learnt that they would be opening on the 9th of Jan. I managed to reach someone (after endless calls & voice-messages),who informed me that they were fully booked. I explained my dilemna & was then given the earliest available date,tentatively. I immediately contacted my mom to confirm suitability of this date for her. When I called Beauty lounge back to confirm, I got through to the same voicemail through which I had left endless messages that were never returned. by the time I got lucky in reaching someone- the voucher had expired. When I explained the situation to the manager, I received the most unprofessional & rudest tone ever. She simply told me it was not her problem & that I should liaise with groupon( although she'd taken payment) & denied ever getting any of our messages/calls. Liar