I am an immigrant in US and graduated in 2018 from a good public university on the east coast. I had a cordial relationship with my advisor during my PhD.
Currently, I am working on my immigration application that requires letter of recommendation from the advisor. He replied to my initial few emails saying that he will get the letter over the weekend/soon and after that have gone completely missing-in-action.
I have been chasing after him for almost a year now. His email is definitely working and he is super active on Twitter. I also dropped him a couple of texts on his cellphone just to be sure.
What are my options? Shouldn't the advisor have ethical/moral responsibilities? especially considering the dire immigration circumstances, and the effect this application can have on my and my family's future in the US.
PS: He is also an immigrant from the same country as mine.
Edit1: I wish it was easy to just meet him in-person. Not only are we on opposite coasts, but he is also not coming to the lab/office these days due to COVID.
Edit2: Should I raise this matter with Department Head? (My advisor is a senior professor who helped department head become department head)