How do I contact Dell's corporate office? Please help?

I have been a loyal dell customer for years.  I actually always had great experience until recently with there support.  I have a dell dj 15 that keeps freezing on me.  I have already had it replaced once and everytime I chat with or call support they tell me to do the recovery cleanup and that only helps for a short while then it starts freezing again.  I called customer service because I had contacted Tech support 6 times and they keep telling me the same things that don't work.  I explained to them that I give Dell alot of business and even have a small business account where I bought many pc's and servers from dell.  The customer service rep said that she would transfer me to tech support.  When I told her I've been there 6 times in the last week she said she would send me over but stay on the line and explain my issue.  After being on hold for 30 minutes I was hung up on.  I wanted to contact the coporate office to let them know that they lost a customer that spends alot of money with them every year but can't find the number.  Dell already lost a loyal customer but I wanted to at least let someone know at corporate support that this has happened so it doesn't happen to someone else.