₦airaland Forum

please, i am new on nairaland.
I have an appointment for visa interview at the American embassy on 7th of December with my wife and son.
We were invited by my sister who is a citizen for her 50th birthday celebration which is to hold on 2nd December and our departure date stated on my application was 20th of November. Unfortunately, i didn't apply early enough so I was given a far date. I tried changing my dates by writing to the embassy to get a closer date but that wasn't possible.
My questions are:
1. Is it possible to cancel my appointment and use my current applications for future applications in order not to forfeit the money already paid for the visa application
2. If we decide not to appear at the embassy what implications does it has on our future visa application
3. is it possible to change my purpose of visit from attending my sisters birthday to spending Christmas with my sister.
Please, I need your advice as soon as possible.