Callers cannot override your ring settings. You may have turned down some other volume control, instead of the ring alerts (or your phone has a glitch).

Caller: Scam

This is visa security…
Hung up straight away!
Here’s the scary bit.. ring vol was turned to minimum, (was in a church at a wedding!) yet phone rang at full volume! Checked it later, was turned all the way down!
How the —— do they do that!