Hi, Can anyone tell me if Citroen are liable for repairing my car. I purchased it when it was 2.5 years old and had a year used car guarentee. This is the story so far :

I took my car to a Citroen garage on Tuesday 25th October 2011 as it had overheated in heavy traffic twice since the beginning of August 2011. I had been told by an AA man that saw to the overheated car in August, that the clip on the coolant pipe had come loose, the clip was tightened and the AA man followed us for 5 miles before letting us go on our way to France. The car was fine until the hot spell at the beginning of October when it overheated again. Once at the garage I was told that they had run a diagnostic test and there was no leak in the coolant system(I was also pressured into replacing my back break pads even though they had passed with no warning in the MOT 2 weeks earlier - I said no to the pads), so they went on to run the engine to get hot and they said the coolant sprayed out and said it was the head gasket that had broken and needed to be replaced, which would cost my around £100 + vat for the part and 10 hours labour, which was offered at a reduced price of £890 + vat (due to the fact I had become very upset, not having that kind of money spare). The desk man said they would fill up the coolant and I could take it away as they were busy(which is what I told my husband on the phone), only to be told 10 mins later that it would be dangerous to drive and he recommended I didn't drive the car as it would cause more damage. Being upset I agreed to leave the car and I was offered a lift home, which I took. I assumed they had started work on the car later that day or at least Wednesday, but when I phoned on Thursday, I was told that they had only just started work on it. Later that day I had a call saying that they had found nicks in my cam belt which needed to be replaced and that they couldn't find a reason for it, but suspected the water pump, even though on inspection they couldn't find anything wrong with the water pump. They said that it would be best to replace the water pump as well, so with the head gasket, cam belt, water pump and all the bits and bobs that go with replacing them, the total cost for parts would be ££340.23 + vat and they would keep the labour charge the same. They also said they would let me know if the cylinder heads had warped or not. I ok'd the work as what else could I do? I phoned to see if the cylinder heads were ok on the Friday morning and was told they were - I also asked if there was a courtesy car available now and they said there would be one back later and I could pick it up on Saturday (They said that they would levi the £10.00 charge for the insurance on the car - although it cost me £12.00 in a taxi to get to the garage anyway). Well I thought all was well until this morning (1st November) when the garage rang again to say that the car was being put back together (good I said) but there was a problem with my air condition pipe - he said the technician had heard a hissing noise and wondered what it was and discovered it was the gas coming out of the air conditioning pipe and this would cost me £120 + vat but they would not charge labour (or there abouts as I got very angry at that moment, so it might have been a bit more or less). I explained that the air con was working perfectly fine when I took the car in a week ago so the damage must have been done there and I said I would not pay for it to be repaired and would contact head office and watchdog if I had to. They said they would see what they could do and that is where I am at now. I have also phoned Citroen head office and explained that I think the whole thing should be covered by Citroen as it is obvious that I was sold a dodgy car and should come under my used car guarantee agreement. They are getting in touch with the branch I purchased the car from and the garage where my car is and said they will get back to me later today. What does anyone think out there? Are Citroen liable? The stress is getting me down so much )-: