Olicana,
The aircraft does not have a tow bar, which is a shame.
I know it sounds a silly question, but have you checked in the baggage compartment behind the rear seats?
edited to say - You MUST be able to locate one somewhere round the hangar? The PA28 is one of the 'commoner' machines. Make sure you have a good root around; I have found myself in your situation dozens of times and never failed to find one yet!