The best way to resolve the dispute over the $4.17 amount is to carefully read the presumed written lease that you have to ascertain who was correct or incorrect in the total rental amount. If you are correct, I would write the landlord a detailed letter explaining why you are correct with specific references to the lease. If you are incorrect in what you paid, I would pay what is owed including any late fee.The concern I have is that your landlord is making such a big deal about $4.17 with the threatened lawsuit for that amount, late fee and the claim for $190.00 in attorney's fees. For the relationship to start out the way it has with the landlord, I would be very cautious in how you deal with him or her in the future concerning the rental.