Hi there

First of all this forum is fantastic!!!
Second, this is my first post please do not be angry if I'm writing in the wrong "section"

i've got a problem with my refrigerator " norpe Saga-135-M-SS" that uses the R404a refrigerant. last week the refrigerator had a leak, the engineer has fixed the leak and recharged the refrigerant gas but i think that wasn't the r404a, in fact the fridge doesn't work well.

what kind of refrigerant could be use instead of the r404a?