What would cause 3 compressor to fail in a weeks time? on 2006 Ford Five Hundred

Like most who have had ac problems with the ford five hundreds I finally went and paid to have my compressor changed. They did expansion valve, drier compressor and condenser I get the car the first day it is blowing warm on passenger side. Two days later all hot. Take it back to pep boys they replace compressor again and all that is involved in that. Get car back and they tell me I need to go to ford to have it reprogrammed. Get to ford a day later and it is not blowing cold but make appt for diagnosis three days later they put it on machine no compressor pressure. Back to pep boys put in THIRD compressor pick up car both sides blowing cold. Two days later car blowing hot air again. Today I take it to another pep boys and they say it had 3 oz to much of freon and now blowing semi cold on driver side warm on passenger. Taking it Tuesday to ford but my question is would the actuator door or something else really make it do this or is pep boys just selling me crap? As a woman walking in I think they are just blowing smoke up my skirt till I go away. Please help.....

Have the negative side of your compressoor harness checked? Have friend that has 2009 Taurus (Same Car) had auxillary neg ground wire run and it fixed problem