Ok, we can only assume that the shop is adding the correct amount of oil, putting proper vacuum on it.
Because it is something different that goes wrong with the compressor each time, this leads one to conclude reasonably that it is due to brand of remanufactured compressor.
The reason is that if it were a case of improper oil amount, not vacuuming the system, or other improper installation procedure, the compressors would fail the same way each time. Too much oil would cause compressor seals to leak each time, not just one time, but not the next, for example.
There are certain brands of remanufactured compressors I have reached the point that I simply wont use due to high failure rate. Four Seasons compressors are one of them. I have had to install as many as 3 of them on the same vehicle in one day before I got one that worked right.
the only other thing you can have done to help ensure the compressor lasts is to have all the lines flushed out when the compressor is being changed, and having an additional in-line filter added. This goes on the inlet AC line right between the line and the compressor. It will catch and small particles of trash in the system that isnt flushed out and prevent it from entering the compressor and trashing it.
But to be honest, due to the compressors failing differently each time, I have to attribute it to poor remanufactured compressors rather than something in the installation process not being done, or not done correctly.
A very good aftermarket brand to go with is Nippondenso, or Delphi