4,000 miles and 3 months ago, I had my timing belt replaced (Subaru Legacy 2.0 RE 06 reg).

Last week, on holiday, in Northumberland, the car suddenly stopped on the A1 in a cambelt-failed sort of way. I called the AA, who sent a local garage.

He asked what was wrong, and I said "If I hadn't had it replaced recently, I'd have said the belt had snapped." He took off the cover, and said the belt was sloppy, and perhaps the timing belt had jumped, maybe it needed a replacement tensioner, and they'd fit one for me. So the local garage took it away. The invoice reads (complete with typos)

"Check for fault with car cut out, found the timing belt loose, dismantle as req, drain off coolant and remove radiator, unbolt and remove timing covers, found two bolts seized in timing cover, found timing bolt tensioner bolt snaped, removed timing belt and tensioner, drill out snaped peice of bolt, supply and fit new tensioner with new bolt, torque tensioner bolt to 35NM. Advise the threads are not good that holds the tensioner in, advise to be drilled out and retaped. Time up engine and refit old belt to test, found the engine to have been damaged when the tensioner bolt snaped, box up bolts etc and left in bits at the owners request. 5 hours £210. Timing belt kit £250. + VAT Total £540."

The garage said to me "we looked in the book after it wouldn't start up and it has an interference engine, so obviously the valves are bent; only the 8 valve engine is non-interference".

The AA then took me back to London yesterday. The view of the AA men who relayed me was that given the existence of a snapped tensioner, there was no point whatsoever in trying to replace the belt, and the garage had ripped me off.

Thoughts? Is it ever worthwhile replacing a belt/tensioner if the belt has "jumped" or if the tensioner is loose?

Thanks in advance.