If I understand the OP correctly, the bbl popped .. he sent it to Benelli, they said it was the ammo but wouldn’t give the bbl back. The ammo co said they needed the bbl to determine if it was their fault but he can’t because Benelli wouldn’t give it back so his only option was to pay out of pocket to get a new bbl.
YOU NEED TO SMOOTH AND POLISH THE CHAMBER AND CHAMBER MOUTH SO THE FIRED SHELLS WILL EXTRACT EASILY.
A FIRED SHELL MAY HAVE DEFORMED BRASS BASE THAT SNAGS ON A ROUGH CHAMBER.