It always worries me with these kwik fix places, it's OK topping it up but what about the pag oil, if this is insufficient there goes the lubrication for all those seals and then the problems begin.
A pressure test alone may not detect leaks over the long term the old gas needs to be removed the system,vacuumed, pressurised with nitrogen/dye mix then oressure tested and UV scanned, only then when it is confirmed the system is intact can the correct amount of fresh refridgerent/pag oil be put into the system