If the repair did not live up to expectations: solving the problem

After a long languid expectation and a continuous row of inconvenience, I would like to get into the room as soon as possible, fresh after repair. But it happens that expectations are not supported by facts and disappointment occurs. Low -quality performance of the work, the mismatch of the approved interior with the received or poor cleaning after repair can do not only spoil not only the reputation of the contractor, but also your mood. What to do in this case?