Order Delayed...again

I am new to the community, and am attempting to become a first time owner of a Studio XPS.  I ordered the machine on 2/13/2009 (five weeks ago).  The order ha been delayed six times.  I have called and found out that the memory (6gb) and monitor (consumer 24" full hd) are backordered.  I called the sales rep that "sold" me the machine, got no answer, and left a message.  I have received no reply.  I e-mailed the sales rep, and have received no reply.  After that, I e-mailed customer service, using the Dell website.  I expressed my frustration and growing anger regarding this situation.  I have received no reply.  I called and asked to talk to a manager.  The rep asked me to tell her my problem, that maybe she could help me.  She said I need to talk to the sales rep, and transferred the call.  There was no answer, so I left another message.  I have received no reply.  Has anyone else had similar experiences?  If so, how do you get someone to engage in constructive correspondence?