[SoCal LS-L]

Sometimes when compressors sit for a while without doing anything, they can partially seize. What probably happened is as you added the gunk from the can into your system, the pressure switch for your A/C allowed the clutch to engage since it indicated a charged system. This overcame the partial seizure and let the internals spin, which were immediately lubricated with the new oil. If I cant spin a compressor by hand, thats a bad sign, like they told you. Its not like they told you they had a nice $500 one..... they said they couldnt even get it. You probably just shocked it into spinning again and you may lose your freon in a few days.... It was nice of them to refund your money anyways, I would have just told you that you totally borked your system with that retrofit-fluid crap. Ill be interested to hear how long it lasts.