Johnnie Jackson had given the Addicks the lead but Matt Ritchie equalised before Austin edged the Robins in front. Sean Morrison added a third before Austin bagged his second and Pawel Abbott netted a consolation for Charlton.
And while Wilson expects there to be enquiries about Austin's signature in the transfer window, he is adamant he will do all he can to hold onto the striker.
"The two finishes Charlie Austin had today were excellent. Seventeen goals this season is a terrific return and there is more to come, as you would expect," he said.
"I'm sure there will be loads of phone calls but that is what we expect with good players.
"We've said all along we are going to try and keep hold of him and there has been nothing really which has made us change our minds at this moment in time."
Source: PA
