The 24-year-old midfielder has reportedly been the subject of a failed £19.7m bid from Premier League outfit Arsenal.
And Leverkusen have now stated that even a greatly improved offer would not land Bender, who is "not for sale at any price".
A spokesperson for the Bundesliga side said: "It's absolutely normal that there has been interest in him because he is a top-level player who is improving.
"But he has a contract until 2017 and he is absolutely happy to stay at Leverkusen."
Bender joined Leverkusen from 1860 Munich in 2009 and has gone on to make over 100 appearances for the club.
He has represented Germany throughout the age-group levels and has now won 14 senior caps.