Best Leaks Check in Milwaukee WI

I have had this company come out for the last 2 or 3 years to service my AC unit. Last year (2020) I paid Action $1142.28 total (2 visits 6 weeks apart) and I'm still having the same problem of no AC. The first time the system was out of freon, they charged it, checked the connections, blew in nitrogen, found a small leak, and put in easy seal. That lasted barely 6 weeks and they had to come out again. The second time they did the same thing, stayed a little longer, took out all the freon, blew nitrogen, said it was a leak again, cleaned out my entire unit, added freon, and it was good for the remainder of the summer (1 month). I haven't had the AC on since then and last Friday I turned it on and it blew out warm air. I feel like whatever they did during those 2 visits was absolutely useless and I paid almost the 1/3 the amount of a complete new unit. My unit is only like 8 years old. Every time they come I have to pay a trip charge and it's a temporary fix.