Workshop recommendation !!!

Hi everyone, I'm new to this site, and I have a 1994 VW Senda 1.8. The person I bought it from said he hadn't used the air conditioning for many years. I've already taken it to three different mechanics; they've replaced pipes and hoses, but haven't done any maintenance on the compressor. It runs out of refrigerant in less than a month. What good, honest mechanic would you recommend? I live in the Floresta/Parque Avellaneda area of ​​Buenos Aires. I appreciate any help you can offer. Thanks and regards.