Yes, read this.
Why would you think they would want to go about some clever plot to claim you did not return the equipment when you did, and you have proof you did, via the cell phone with dates and times? They're not in business to torment you, they're in business to get the job done. They've probably spent all the time they want to spend on you anyway, and don't give a hoot about you. Your paranoia is really showing on this one.