Dell "Customer Service", either disconnects my call and will not answer my questions.

Alright, 

I ordered a new computer a month ago. When it arrived it was defective. I knew what was wrong with it, but had to entertain the tech and do has he instructed. Once he came to the same conclusion that I had. He agreed the computer was defective. 

I asked for either a refund or a replacement. This was Feb 27th, and they said they would ship me a replacement computer in a matter of days. That seemed fair to me and I agreed. I received an email from Dell on March 1st saying they had shipped my new computer to me, and I should receive around March 12th. Friday rolled around )which was the 12th) and the computer did not show. I figured it might take a day or two, so I was not too concerned.  Sat March 13th, I received an email stating my order would be delayed until March 27th. This confused me, So is my question at the time was, had my computer shipped or not? Why would I get one email stating one date of delivery with receipt, tracking number, order number, and then get a email later stating that my order had not been processed yet? 

I called today, and the "Customer Service Agent", (I use that title loosely) instead of listening to me went though whatever script Dell has them read assigned by whatever topic. When he finally finished his spill...I asked him about my order and why I was giving 2 dates. In response he put me on hold and disconnected my call.

The second call was the same. I let the guy read his scripts and I then explained my issue. I was placed on hold and then disconnected again.

I called a third time. This time, I was a little more forceful and refused to be placed on hold. I wanted to know the answer to my question. This time a lady explained that the computer I ordered was on back order. So, I asked why was I not notified and why did I have documentation of my order being shipped then?

She could not answer...I asked about my money being returned. Of course it can, she said. I am in my 30day grace...30days grace? So a product I paid for, and do not have...You have a countdown on it? I let it slide...no need to open a whole new can of worms.

So, Dell can someone answer my question? Is this the true way Customer Service is handled? Regardless, this was my first and will be the last purchase I make from such an unprofessional company.