Dell Computers Unauthorized Repairs, returned laptop damaged, lying Nationwide

I called Dell to get a fan fixed on a Dell Laptop. They sent me a shipping box and paperwork to fill out where one had to specifiy repairs requested.  I sent it in, called and spoke to a representative who swore she would personally see my repairs through to the end (I never heard from her again).

1) Dell replaced my hard drive without my consent or knowledge & I lost all my software and 5 years of PhD research

2) Dell lied and said they never sent me paperwork to fill out regarding repair work. (Really-- then how did they know what to repair?!

3) Dell lied-- first saying how hard they worked on my hard drive, then later in the SAME conversation, claiming when the laptop arrived, the computer would not even boot up (Really? Why didn't Dell immediately call me to discuss or inform me?) The laptop WAS working when sent in. I just needed a fan.

4) The sound no longer works on my returned laptop

5) The power cord no longer works on my returned laptop

6) Customer service managers are rude, yell, and LIE.

I will never buy DELL again. If there is a class action suit-- let me know !