Selling service that they not intend to deliver

Bought a voucher from Dean where I am eligible for 3 treatments at Perfect 10. The voucher say bookings must be made week in advance, but earlier appointments may be available. I tried to make bookings last year, but the moment I mentioned the voucher they were full.<br> I decided to make a booking without mentioning the voucher and could choose my time? <br> When I arrived we were 2 costumers and 3 the******s. But when they saw the voucher They apparently squeezed me in as they thought I was a paying customer...After a huge argument the manager said she would do me. She started my facial so ruff I stopped her. When I left there was no clients......Dean was called an pledged my money back, but still did not receive a sent<br>