Contour wrap a total con :(

Hey everyone, as some of you may of known, I've just got back from a girly weekend in glasgow which included a spa day on sat where i was having a contour wrap.
According to the spa's website, you are GUARANTEED to lose a minimum of 6 inches off your body and keep it off for 30 days or your money back. Needless to say i was very excited about having it done, and so was my sister-in-law Becca.
Well Becca had her's first at 11am, came out 2 hours later saying she felt no thinner but would maybe tell when she got dressed (we were lounging around in swimsuits and robes). The girl that did her wrap came out with a certificate saying well done, she had lost 13"!!!!!!!!!!! As you can imagine I was even more excited then.
I went in for my wrap at 3pm with a different therapist to Becca, and lets just say you can't be shy to have it done lol. Firstly she took may starting measurements, I noticed she didn't overly pull the tape measure tight but didn't think too much about it and plus she measured my body in a million different places...for example, chest, bust, under bust, rib cage, waist....well I know full well there's pretty much NO difference between my 'under bust' and rib cage!
I was then wrapped up and left for an hour for it to work its 'magic'.
Once all bandages removed, she took my measurements again. well I could see her writing done the results and there was litterally only a difference of eg 0.2" for each area. And I could tell the girl was feeling nervous as she could tell my mood was deflating. She then left the room to work out my 'total loss' and for me to get dressed and meet her back out in the lobby area where the other girls were.
The lass came out and with a smile announced I had lost....surprise surprise....13 inches!!!!!! I knew instantly it was wrong and asked the girl if i could have a copy of the mesurements. She was very reluctant but knew she couldn't say no, so becca also asked for hers.
And this is where it gets better! Firstly they didn't even add it up!!! looked through my chart I had actually 'lost' 8.4 and Becca had 'lost' 9.2, so guessing they tell everyone 13! Then we compared against each others....According to their measurements of us, me and Becca are pretty much exactly the same size....when in reality becca is a very tall, slim 12 and I am a large 14....in the very first measurements they had made becca larger than what she actually is.
Needless to say we were both extremely upset.....Becca was about to complain but it had gonna 5.30pm and the lasses had gone home. I have sent an email of complaint last night to the spa and requested a refund....it cost £109!!!!!! And I know Becca shall be doing the same.
It put a real dampener on the weekend and feel so conned. never again!