when does phone service transfer to new phone

I did all that a few hours ago. Got a popup from Verizon asking me to verify my identity with last 4 digits of SSN, which I did, and which was accepted by them. Still can't use the iPhone to make a call.

Call my provider. Which does not allow phone calls. I have now been on online chat with them for over an hour. Problem still not resolved, although now that there's an actual person working on it (not a bot), things are looking up.

I didn't have that number. It's not on my bill, and I didn't see it on their website. I did choose the "you call me" option, a couple of times. Got automated responders that kept hanging up on me. That's when I opted for the chat. Almost 3 hours in now, and the (live) agent says they'll have to put an IT ticket in on it. Three live agents have tried, and couldn't solve it. So it's not something obvious. They don't think it's the phone.

Update, after 3 hours with Verizon support yesterday and another hour plus today: the eSIMs provided in the iPhone don't work, can't be activated. I'll have to go to the local Verizon store and have a physical SIM card put in, then a Verizon agent will call me on Monday to activate and make the switch. What a mess. Cautionary tale about eSIM, maybe.