Timing Belt Issue

My water pump was leaking a while back and I had a shop install a new pump and timing belt. A month later the belt popped off at 3am in downtown Atlanta(pouring rain no cell phone, etc etc). I took it back to the shop and they said the tensioner went out and charged me even more money. Is this normal? For some reason my ass hole feels sore that I'm paying them twice in a month to install the belt. Should they not have checked the tensioner the first time? Or is that a bull shit reason for why they fucked up the first time?

Also no valve damage from the belt coming off for those keeping score.

that was bullshit, anyone doing that job would be checking the tensioner to even be able to get it out the door without F'ing up so they could get paid.
I think they left it loose.
These things are tight as hell even with the tensioner loose, until you put some load on the engine.

I read somewhere that you should replace the tensioner with the belt. So it is not normal for this to happen, it was their fault.

Wow yeah, I agree with the two above posts. Those idiots should have replaced the tensioner with the timing belt! They're not expensive, and it's idiotic not to do so. Or at least make sure the current one is good! This is definitely their fuckup!

sadly it is possible they never actually replaced the belt if the car was already running , they would think you never would know the difference, unless the cover was missing.

you specified for them to do a water pump and cam belt
by rights the belt also usually means tensioner and idler pulleys as well
check your receipt/invoice
it should have every part replaced on it
if they done the tensioner,it came off, they are at fault
if they didnt do it, ask why
its considered normal practice to do so
i know i'd be fired up
you should be to if its there fault

I did not replace my tensioner until my third TB change. Unless there is play or noise in the bearing it should not fail. It really does not have that much lateral force on it. It is not a bad idea to change it, but it is just not usually essential. I have changed my water pump twice in the past without even taking off the TB cover (poor quality aftermarket unit) so I am not even sure what these guys did. It sounds like BS to me, too.