First, you have a strong argument that the subsequent written agreement with the management company controls over any conflicting language in the original lease regarding the payment due date.
Second, if the landlord is charging you more the proscribed late fees in the lease, the landlord is over charging you.
You should consider putting your concerns in writing, quoting the particular lease provisions at issue, attaching a copy of the lease and the subsequent agreement, and politely requesting a refund of the late fees/overcharges. If your landlord fails to comply, you can sue in small claims court.
Not sure what you you mean by the "allowed late fee". Whether or not the landlord can charge a late fee will depend upon whether or not the lease or rental agreement has such a late fee provision, as well as whether the amount of late fee is reasonable. If there is no such provision, the landlord cannot charge a late fee.
Therefore, it is likely you have a claim against the landlord for improper or overpaid late fees.
Frank W. Chen has been licensed to practice law in California since 1988. The information presented here is general in nature and is not intended, nor should be construed, as legal advice for a particular case. This Avvo.com posting does not create any attorney-client relationship with the author. For specific advice about your particular situation, please consult with your own attorney.
If the agreement allows you to pay as you describe, then you should not be charged any late fees, unless you are not actually paying on time. Take the agreement and your payment records, including anything from the landlord regarding late fees, to a local landlord tenant attorney for a consultation.