It’s getting a bit quiet on here, had the car serviced at
AST but it now needs new rear pads. After this continued heat, I thought it’s really time to get the ac sorted. The garage pulled a vacuum on the ac system, and said it was not leaking, so made the call to regas. Well got half way home along the hogs back with some ac, but it soon started warming up again.
Not sure if anyone knows what the ac refrigerant pressure should be? On vcds on my old b6 with original 2002 gas it shows as 13 bar, it struggles on the really hot days but still works.
It sure is

we're the last of a dying breed, I reckon.
The best I could find, for the B7, is "With your
AC on, your circuit
pressure gets to somewhere between 8-12 bar normally with a high of 14", but obviously you've got a leak, I can't see where exactly from your photo, except the engine mount? The shrader valves can be the culprits sometimes and they are normally pennies to replace, the other common fail is the pressure switch, any fault/leak/low pressure, there and it will switch off the compressor for protection.
If you're getting heat whilst your A/C is on cold (the matrix is always 'on') then one or more of the flap motors are not funtioning correctly or dead, I had to replace the red one on the passenger right, as I had warm air the passenger side. It's worth doing a basic reset on them (mandatory after flap motor replacement anyway) via VCDS or OBDeleven too, as that may be all it takes.
I've been very lucky with mine: wasn't working when I got the car in '18; took it round the corner, regassed it and that worked with a rattly compressor for 4 years or so; when that finally died (after a regas) I had a new one installed, which was only about 250 quid; been perfect since (and silent) except for that flap motor, which was an easy fit and cheap eBay second hand, out of an RS4, I believe, no less.
Don't try and fill it yourself with those kits you can get - it's not proper r134a, they have propane in them, since they're not aloud to sell real r134a direct to the public any longer. The best way and to save money is have a garage completely evacuate it, fix the leak problem and take it back for the regas.