1 iPhone and 1 Cell Number Damage (TFA problem)

Hey there,

Yesterday my wife old iphone 6S fall down in to water and broke the screen within cell simcard inside

So i bought her the new one 7+ with new cell number and try to login for the first time with same apple id in old 6S..

But the problem start from here..

My wife old 6S used TFA with 1 device (old 6S) and 1 cell number..

when start login her apple id to new 7+.. the 7+ need 6 digit code TFA whichmean send to old 6S and old cellnumber,

meanwhile we can't access the old iphone and old cell number to get this 6 digit code..

So we stuck with this step from yesterday morning..

So we try this guidance :

https://support.apple.com/en-us/HT204921

In apple id web login status, it said we must wait the account recovery in 6 days.. :(

There is anyone know the other ways to solve this problem?

This TFA method is annoying when u just hav 1 device and 1 cell number..