Intermittent engine starting issue?

Hello,

I am in desperate need of your advice.

I recently purchased the vehicle listed above TDI S Line second hand with 47k on the clock. 65 plate.

I was driving it back from work the other day when I stalled it in the middle of the road. The car would then not restart for me at all.
I managed to get it going again shortly after and get it back home. I took it to a local garage who pointed out that it does not seem to start once the engine is hot, i.E. After a short drive if I pull over in the garage and turn the engine off and on again it does not start up again. Once the engine has cooled down a bit it then it starts first time.

There are no errors on the dashboard at all.

I've taken it to a local garage who are messing me around and not doing the investigative work necessary. I asked them if it was a battery issue as this was a secondhand car that I'd bought not long ago and could have been left standing. The garage told me that they'd tested the battery, and it was in working condition. They did not seem to think that it was an issue also because the engine starts for the first time when it's cold i.E. It does not struggle at all to start when the engines are cold, and there are no sort of cranking noises coming from the engine.

When the engine does not start there is no cranking over of the engine at all, it just appears to be dead.

Please can anyone help, I'm absolutely gutted about my new car.

The garage have done some checks, and said that it's not an issue with the clutch switch/sensor (as it's a manual drive).

Thank you so much.