I can definitely understand that but it sounds like you have about a week to get this resolved. The closer you get to the end of that week, the more last minute airfare will increase. Relying on DHS/CBP/INS etc to resolve a major issue in less than 6 days may not happen. Unfortunately we have tens of millions of illegal immigrants living in the U.S. (more than any other single country in the world). I'm sure you're aware this uses up considerable DHS resources, causing law abiding people like yourself to be treated like back of the bus. I know Europe has some immigrant issues too but luckily that is spread out over almost 30 different countries, so no single country has to bear the overwhelming burden like we do. I know it's $2800 bucks but waiting till day 6 or 7, it may be three times that amount.
On another note, it sounded like at first
DCL was hesitant to take up your issue. Didn't you pay your port fees to DCL? Weren't the port fees supposed to cover manifests, customs documents, passenger lists, etc. To me, if I paid my port fees to DCL and the port fees didn't cover what they were supposed to cover, that is definitely on DCL to get that resolved since you paid your port fees to them to handle on your behalf. Just saying.