Fill out this form.  Don't forget to tell them you need a return shipping label either emailed or mailed to you. Give Dell 3 business days to reply or so This will escalate the issue, let me know what they say? Z..............
I had ordered a Dell Stereo USB Monitor Soundbar AC511 based on the recommendations of the Dell representative on Chat for my U2312HM monitor: 05/09/2014 10:33:05AM Agent (Zaldy M): "For the soundbar compatible to the U2312HM monitor, we got here this Dell AC511 Stereo USB Sound Bar for $35.99." 05/09/2014 10:49:04AM Agent (Zaldy M): "So you are purchasing this Dell AC511 Stereo USB Sound Bar"05/09/2014 10:49:07AM Shailendra: "ok"05/09/2014 10:49:40AM Shailendra: "which u r confirming is compatible with the U2312HM monitor"05/09/2014 10:49:56AM Shailendra: "if so, then yes"05/09/2014 10:51:02AM Agent (Zaldy M): "Yes, it is compatible with Dell U2312HM monitor" and when I received the item it did not fit and after 5 HOURS of calling and waiting on hold with VARIOUS departments of their Customer Service + Technical + Returns + Home etc NOBODY is willing to solve the issue and everybody keeps telling me to call another department. They have even acknowledge that they gave the wrong information: "Sorry for the confusion, but upon double checking the sound bar is not compatible. Here's what I can advised you to do you need to call the Customer care department so that they can set up a return for an exchange or a refund. We sincerely apologize for this inconvenience. The direct phone number is 800-624-9897." Why should I go to the extra trouble of returning the item and then ordering the new item and waiting again?? I have already ruined my entire day just calling and being on hold with DELL support. Shouldn't they do something to make this easy for me since I ordered the item based on what THEY recommended and trusted them???? 
Wrong item ordered based on chat with Dell