Aircon Refrigerant

[adjust8r]

I recently got four new Potenzas from a nationwide tyre suppliers and fitters and as part of the deal, they recharged my aircon and changed the refrigerant FOC. This process took about 45 mins and the machine they used was a Bosch with various palstic bottles of liquid, tubes attached to the aircon system of the car.

They advertise this as improving the cold flow from the aircon. However, the aircon is not colder and if anything, it is not as cold as it was beforehand. I phoned them up and they advised that it should be at least as cold as it was before hand...they implied that maybe I imagined it but to bring it back if it didnt improve.

Techy question, is there any particular type of refrigerant that must be used for a Lexus is220d...or are all refrigerants the same? Is there something simple that they may not have done properly that could mean the aircon is not effective.Does changing refrigerant in a lexus involve anything over and above than other vehicles? any help appreciated. I would like to be armed with a bit of knowledge before going back.

Cheers