Question

I have a Trane Heat Pump system installed in 6/2007 that was wired incorrectly. At the first severe cold snap the entire outside unit was completely frozen. Ice build-up on the inside of the outdoor unit reached the fan blades and the noise was our first indicator of a problm. We were told the defrost cycle was improperly wired. After rewiring and several days of defrosting the unit appeard fine. This year at the first severe cold snap we had problems again. This time we were first told that the heating elements (3) were not all wired properly and that the heat pump needed them to supplement the heating and they rewiried it. That night we heard a loud niose coming from the outside unit and shut it down. The next morning we were told the jumper wire they installed was loose and they tightened it. An hour later, the same noise and now they say it needs a new compressor. I'm not sure I'm getting the correct story and am asking for suggestions on what to do and who to contact.