Spirit Airlines Worst experience in my life Miramar, Florida

I booked a vacation using Spirit Airlines in November 2012.  I went to fly out on March 20, 2013 and found that the seats I had booked 4 months earlier had been changed.  I paid a lot of money and booked far in advance to make sure that I was able to get the big front seats.  I was traveling with one person who happens to have a serious illness and another that has severe claustrophobia.  Spirit totally ruined our vacation.  This is the last chance I will have to go on vacation with these individuals and we spent days on the phone with no help or response from spirit airlines.  They have been no help whatsoever and have lied to us.  They have the worst customer service I have ever had to deal with.