The air conditioning system contains lubricating oils that circulate when you use it. This means the system needs to be switched on 100 per cent of the time. Failure to do this will result in the joints drying out or (worst case scenario) the condenser seizing up. This usually happens when people switch the air con off for the winter months and isn't something that would be covered by your car's warranty.

If the issue is related to a manufacturing fault then you will have grounds to demand a free repair. However, given that you've owned the car for longer than six months, you will need to prove this is the case. A mechanical inspection by the SEAT dealer should identify the cause of the fault. Or you can get a second option from an independent automotive air con specialist if you wish to dispute the dealer's claim.