anyone?????

hi, dont know if anyone can help but i bought a brand new citroen c3 in june 04 and have had endless problems with it. It is always breaking down and then they never have a courtesy car for me. Last month i broke down again and had to be towed back to the dealership, this was 2 days before my warrenty ran out. I spoke to citroen head office and said that i would like an extra years warrenty on it because of all the problems i have had and they agreed to an extra year but only on anything engine related. Today i have broken down again this time something to do with the gear box. I have told them that i am not prepared to pay for it but they said they have to inspect it 1st then decide. I am so fed up with this car it has never been right from day one. what rights do i have??