Corsa Timing chain fail at 24k miles

We have recently had a problem with our 61 plate Corsa 1.2. We noticed a tapping/ticking noise coming from the engine and immediately called the AA to come and look at it. He had a look at a few things and confirmed no problem with the cam shaft as he originally thought. Said it might be the related to the oil and oil filter. We didn't drive the car for a few days until we could get it serviced and told them of the issues. They picked up the car and drove it to their garage, performed service and advised on three things. Front brakes, spark plugs and some corrosion in the coil pack. We didn't authorise these to be repaired.
They then were returning the car and the timing chain snapped on the motorway while they were driving it, causing a lot more damage to the engine, cam shaft etc. The car has only done 24000 miles. We thought these issues would have been raised during the service but they weren't. The garage are now wanting us to pay for a new engine and whatever else needs done which is going to run into the thousands.
Do we have any rights regarding this? Is it reasonably conceivable that they should have identified the problem with the timing chain from the noise and advised on a repair and told us the car shouldn't have been on the road? By them choosing to drive it with this problem and it being in their possession, we feel it is their responsibility. Is this something Vauxhall could be responsible for?
Thanks in advance for any help!

Steve