Do AC companies have officiall service centres or they send local mechanic disguised as authorised technicians?

I have my 2 year old Ac stopped working properly and cooling. I bought a local mechanic and he further damaged it now I'm dependent on official company technicians but I got to know that these AC companies don't have any authorised service centre and they send these local road side technicians calling them authorised service technicians. If any has experience of getting their Ac repaired by these company technicians please share. I'm very much troubled. I've spent this whole summer without ac and afraid to get it repaired by any local technician. Please don't advise to get it repaired from urban company as they to have this local roadside mechanics disguised as official mechanics from service centre