£15 for the price of £40 beauty voucher ?

I bought a groupon deal and paid 15 to get 40 worth of beauty treatment. I had the treatment and she was fantastic, I bought this voucher from her as a in house deal but I am out of the country and cant make it. The voucher runs out this year 2012. http://www.phoenixbeautypoint.co.uk/ The place is 5 minute walk from Oval tube. Olivia