Feedback on service experience

I am extremely disappointed in the service I received on the Dell Optiplex AIO 7490 we ordered. When the computer showed up, I tried to hook a second monitor up to it using an HDMI cable. This did not work. After a short amount of troubleshooting, I determined that the HDMI out was not working. I called Dell support. The person told me that they had to replace the motherboard - which I already knew. When the onsite tech showed up and replaced the motherboard (a refurbished one), the replacement part was bad. The tech reported that the replacement motherboard was bad and was told that she had to ship the old motherboard back (instead of re-installing it in the computer which would have left us with a working computer). I talked to support again - I was told to "rest assured the replacement motherboard will be shipped today and it has been tested so it will work." I was also told the replacement part was in stock. They refused to replace the computer with a new computer as they claimed it was over xx days old. Which was impossible as I had just opened the computer when this call started. The Dell support people took several days to get another motherboard to us (said they were back ordered) and the second motherboard was bad. At this point we talked to a supervisor who approved a replacement system for us. I told him that it was already approaching three weeks without a working computer, that they obviously had them in stock (if I ordered a new one the web site said I could have it in 1-2 days) and I asked him to expedite this so we could have a computer up and running. The replacement team contacted me, and I approved the build within 30 minutes. However, 3 days later, I had still not been contacted about the replacement. When I did get an reply, I was told they were waiting on my approval (which had been sent 3 days ago). Then I found out that the replacement system would take another 2 - 3 weeks for us to receive.

In all of this, (I have names of most of the people I have talked to), I was told several times things that turned out to just not be true. I was told they would ship the computer out of stocks they already had, and then was told they would have to build it. I was told they motherboards were tested, when the faults (the second was a power bus fault which would have appeared on any reasonable functionality test) clearly showed that was very unlikely to have occurred. I was told people could not contact other departments, but later had somebody do exactly that. I have been using Dell computers for well over 30 years and have been in IT for well over 40  - this has been the absolute worst experience with Tech support I have ever had with ANY computer company. I have no idea where to give feedback other than here. It would have been wonderful to get the "how did we do?" form, but I have not.