Groupon UK - Refund on oakland retreat

We recently had the worse experience that I booked through groupon under booking ref: *****
It was advertised as an exclusive retreat for couples. OMG as soon as we arrived it was the shock of our lives. Apart from the hut everything was rotting away , dirty or full of mould. What was described as the 'SPA" was a hot tub full of insects and mould that was unusable and if you wanted to use it just for you it was an extra cost. Laughable.
Driving into this so called " retreat" was like driving into an industrial estate .
Totally appalling an absolute con.
Everything we thought was part of the so called package you had to pay for.
An absolute con.
The whole experience was absolutely unexceptable and I demand a full refund immediately.
I have used groupon many times and have never had an experience like this.
I suggest you investigate what you are advertising for this so called retreat as I think I will not be the only complaint.
Please see attached pics we took of this dumping ground.
If we were not so tired I would of turned the car straight around. I even tried to book a hotel without success for the night just to get away from there.
And lastly the so called breakfast was a waffle that you put in a waffle machine.
Totally unexceptable.
I want a full refund immediately or I will be taking this further . Still in a state of shock.

Regards

Mike