Hi!
I'm in the same boat as you! I hate, hate phone calls! I was applying for masters programs a few months ago and it was h e l l for me. I felt like I kept tripping over words and felt like I couldn't get my points across- like I wasn't as "smart" as I seemed to be on paper. I find it hard not being able to tell how people react over videocall. It's also abit strange to me because video call like a friend thing? I nearly felt like I was slipping into how I'd act around friends.
Sorry for all the ramble....but something that helps me as having a rough idea of what I'm going to say. Google questions they might ask, they tend to ask alot of the same questions so it might not be exactly what you have wanted to say but you wouldn't have been caught off guard.
Like someone said above- you could always hang up- people wifi gives out all the time so they won't even think to much of it if it's videocall or phone calls drop all the times! It's not like you can run out of a face to face interview!
Sending you lots of good thoughts xxx