Can a landlord withhold a cash for keys addendum for a garage not being cleared?

I surrendered my house and took a 3 month rent free lease to find something else. The lease included a cash for keys incentive for a dollar sum on the moving day if the home was broom swept clean. On the day the rooms were clean but the garage was not. The agent agreed to a reduced cash sum and said it would take a week to get the reduced check. Subsequently he emailed me to say it was an all-or-nothing deal - no money. I pointed out that the addendum allowed for a reduced sum to remove debris left behind. What legal recourse do I have?