Mk5 GTTDI won't start

Hi I have a 2004 GTTDI, I was driving in 3rd yesterday and the engine started struggling to gain speed like revs dropped as I was accelerating, I put it into 4th and tried again then the car just completely cut out and will not start and makes a high pitch noise when trying to turn over, the RAC came and said it's possibly but cam belt but it hasn't come off or snapped, theirs no compression in the engine, could anyone help as iv only just bought the car recently and don't want to be ripped off for money I haven't got at a garage, I need the car to go back to work Monday otherwise the whole family will suffer ?

Was just the cam sprocket cover removed to confirm the timing belt?
How about the tensioner? Still tight? Dial inside window?
Do the ribs in the timing belt appear ok? Shredded?

To diagnose engine timing, the indexing tools should be installed. This will confirm if the engine did not lose time

If engine timing is intact (inside spec) you can move to air/fuel delivery checks

Good luck