silver lining aviation

Purchased a Living Social voucher for $149 for a powered hang-glider flight with Silver Lining. They were out of town when I wanted to schedule and I never made an appointment (voucher did not indicate company would out of town often or I would have done it sooner). Voucher expired without being used. Vouchers are supposed to have value for the amount you paid for them, even after they expire. My Living Social account said that it was already redeemed and no good. I contacted Silver Lining twice about this and said I would be happy to use it next year in Florida or in Michigan and pay the difference. Could they please reverse the redeemed status. No response to my e-mails. I lost $149 and never got to take the flight I really was looking forward to:( So disappointing that they would not honor the voucher even though that is Living Social standard policy.