The wife ran our A6 all the way out of gas. I have put close to half a tank worth of fuel into it and it will not start.

I have cycled the key to listen for the fuel pump to run and I think I hear it kick on (never really heard it that loud to begin with.
I gave the fuel tank a good banging.

All to no avail, just turns over with not even a hint that it is getting fuel. Is there a fuel pump reset switch like on Fords?