No, Dell does not repair monitors. Even most local computer repair shops don't really fix monitors (only very minor issues). Finally, you can't "fix" a damaged TN/IPS display-panel. Check your credit card. Some offer accidental damage protection on purchases. I'm still not sure how you managed to break it. Did it fall ?
I have damaged panel by accidentally putting too much pressure on the screen when I was mounting the screen. There is a circle of damaged pixels where my thumb is. Its heartbreaking as the screen is new and I didn't realize how sensitive the panel is to pressure. Anyway I reached out to support who simply replied that I have to buy a new one! I asked about an option to repair but they never even bothered to reply so I am asking here.  
AW3423DW, I damaged the panel