The Addicks accepted four bids of around £150,000 for the 31-year-old forward, one of which was from Luton Town.
But having seen his switch to Notts County collapse earlier in the summer, Benson turned down moves to Luton, Rotherham United and Bournemouth.
Town chief Gary Brabin admitted that they had tried to sign other players before the deadline and not all their moves had been successful.
He said: “Yes there were people who were on our radar who we didn’t get.”
For the full story, see this weeks Luton News / Dunstable Gazette