2008 Passat cambelt change advised that thread and helical worn

[ashmill]

I have a 2008 Passat bought in 2012. Been using it for a daily commute of about 10miles roundtrip with the odd weekend away from home but I do no more than 8k miles annually.
So I have done about 45k miles since I bought the car, and the cambelt had been changed at the time I bought it. The 4 years is up for a change of cambelt but not the 80k miles advised.
I'm starting a new job in a week's time and decided to get the cambelt changed (just in case) as I intend to use it as my commute car, now commuting 110miles weekly.
The place I took the car to change the belt is a VW/Audi specialist garage, not a dealership, and they called to say it will take longer than a day to change as on opening the water pump and cambelt areas, they found that the thread that holds the belt in place had slipped out and the helical is worn. I don't have a Scooby's what all this means and the garage can't tell me the additional costs until their head doctor (I think he said head doctor, over the phone) comes out and takes a look tomorrow.
Really panicked now as I need to plan ahead. I wouldn't want to pay thousand for an 8 year old car. Will I get the car back in working condition if the cost is excessive? Will it be okay to change the belt but leave this work out. Are these threads as in the threads we have on nuts and bolts? Can they be repaired without changing the whole engine block?
Does anyone have an idea what all the jargon means, and how this could have happened as I bought my car from a VW dealership and had only ever serviced it at my local dealership as well. This is the first time I've sent it to independent VW specialists for work done.

[zollaf]

a stud screws into the head and holds the tensioner in place. it sounds as if it has been repaired with a helicoil in the past and they are not happy with it in its current state, so need a new helicoil fitting. some garages do this themselves, some get a bloke in a van to come and do it for them. should only cost a few quid if it just needs a new one winding in. maybe it will need an insert, who knows. google helicoil, thats far easier than me explaining. but dont panic, its routine.

[ashmill]

Thanks for the advice. Will Google the term. You've put my mind at ease.....albeit for 24 hours....