you should start by disputing the charge if you used your credit card for the purchases, it is highly likely they will side with you if you have the information from the UPS store employee and refund your money.
I made the serious mistake of buying a monitor from Dell. Actually it's a pretty good monitor. But I will never deal with Dell again.
First off, they shipped me three monitors. I sent two back, but apparently I goofed and put the identical label on both boxes. Dell claims they only received one; the delivery confirmation only shows one - probably because there is only one tracking number. At the UPS store where I left off the packages I got a letter from the owner stating that according to his records I dropped off two monitors for Dell. Dell doesn't want to hear about it. UPS considers it to be my problem.
Throughout the whole process I had many conversations with Dell agents and Dell performed with an astounding array of misinformation and contradictory information. Several times I was told the whole thing would be resolved in (however many) days. I would eventually call back to find that nothing had changed. The whole thing took two months before they finally essentially told me to kiss off. I tried to talk to someone higher up and they promised someone would call but it didn't happen.
If you are thinking of dealing with Dell I would advise STRONGLY AGAINST IT. It might work - you might get BURNED !!! Dave G