put someone through the mill idiom  informal      
 使(某人)饱受折磨;(尤指用大量问题)为难(某人)
to cause someone to have a difficult and unpleasant experience, especially by asking them a lot of difficult questions
  I had the interview this morning - they really put me through the mill. 我今早去面试了——他们真让我受了番折磨。