Check to see if the compressor clutch is actually engaging.

If it does not engage when the AC system is engaged (cycles on and off) when the AC is suppose to be running then most likely either you don't have enough Freon in the system (leak) or the max pressure switch is bad. Could also be a stuck expansion valve. Depends on what you find and how you diagnose further to come up with the true issue.
At this point a set of gauges then comes in handy to continue testing.

There are many more things that could be bad, this is just a primer.

 

Who ever did the service should know, what the problem is? What did they say?

 

Didn't say anything other than working fine when spoke on phone. Unfortunately picked up car after they had closed so have not yet been back to question.
Its a fast fit place as such that just plug the AC R2D2 in and let it run. So believe is all filled correctly, just not working, hence asking re relays etc and how they effect air con light on dials if faulty.

 

On searches found that blocked pollen filter could be an issue, but blower strength seems fine.

The cabin filters (there are two stacked together) is a maintenance item. You can (should) do it yourself.

The most difficult part of the job is getting everything that was removed from the glove box to fit in there again!

 

Is the compressor turning when it says it is on? Sometimes the clutch plates wear so thin that it can n longer engage.
What I was able to do is remove the face plate on the clutch and then remove one of the 'shims'. On his vehicle it just appeared to be several washers of different thicknesses. I removed one- put it back together and it works fine.
Removing a shim just allows the clutch plate to get closer to the face.

Of course if your clutch is engaging now- then you do not need to do this!