Help - US citizen flying to Lagos, Nigeria on Monday but my tourist visa is delayed

I applied for my Nigerian tourist visa Oct 18,2023 and was told it would be delivered to me Dec 8,2023. I have contacted OIS who said there was a visa shortage 2 weeks ago. I fly out Dec 18 and not sure what to do at this point. I have been emailing them to see what to do, but they say they are waiting to get back my passport/visa. At this moment, not much has been done on their end. Apparently, they don’t have my passport, it is at the embassy. There is visa on arrival but it's for businesses. Should I get a second passport? Should I email OIS back to get my passport back? Should I just wait and extend my flight? I'm stuck.