Nothing can do now after the fact besides what is already suggested.
Now after you find the phone you can set it up with google (if linked to gmail account) to be able to find phone, remote wipe, and turn on ringer.
Another option is a program called tasker (similar to If This Then That but with much much more capability and conditional logic). One of thousand things you can do with tasker is set it up so that if a specific number calls it X amount of times, it will turn volume back on.