Oh my god.
Amazing, mental, just crazy.
This is what you should have done:
Sold the Punto, saved/borrowed £500-£1000 and brought a 10 year old car thats in good nick and runs. Used that for a year to get from A to B whilst saving for your next car.
At the end of that year you could have gone and brought something a bit nicer than a Clio.
I'm not a fan of Clio's but can see they have a place in the car world, cheap city A to B transport. Nothing wrong with them, like Fox has said not everyone can afford a BMW or £20k car and that's fine, no really it is. There is no shame in driving a 4 year old Clio. However you have been mugged off, totally mugged.
Please try and take it back, say you were drunk do anything. If you need a car really quickly/that badly we will help you find one.
Infact just for the lolz, if you manage to take this car back, I will personally loan you the money to buy an A to B runabout that'll last a year with a stupidly low rate of interest.