They shouldn't have replaced the compressor twice. If it keeps raising then you don't have a problem with the bags getting air you have a leak somewhere.
I would say if they have replaced the bags and compressor, then you have a problem with the height sensors, the air lines, or the valve/valve block. Worse case (least likely) is the computer that controls it all could be faulty.
I would say if they have replaced the bags and compressor, then you have a problem with the height sensors, the air lines, or the valve/valve block. Worse case (least likely) is the computer that controls it all could be faulty.