The servicer must credit a payment to your loan account as of the day it is received. Some consumers have complained that they’ve been charged late fees, even when they know they made their payments on time. To help protect yourself, keep detailed records of what you’ve paid, including billing statements, canceled checks or bank account statements. You also may be able to check your account history online. If you have a dispute, continue to make your mortgage payments, but notify the servicer in writing (see Sample Complaint Letter) and keep a copy of your letter and any enclosures for your records. Send your correspondence by certified mail to the address specified by the servicer, and request a return receipt. You also may wish to fax or email your letter and any enclosures. Be sure to follow any instructions the servicer has provided and confirm the fax number or email address before sending your letter. Keep a copy of transmittal confirmations, receipt acknowledgments and email replies.
I addressed the issue of "aging payments" on desks and in mail rooms many years ago. It is all the same game still going on so many years later.
I do not agree with sending payments certified mail, though. Delivery Confirmation will tell you online (in printable form) exactly when your payment was delivered by the post office. The post office itself scans the delivery so there is no reliance on servicer drones. That way you miss the servicer's "only certain employees are authorized to sign for Certified Mail" game. Those "certain employess" seem to take really long lunches and have lots of vacation days; rarely present. Delivery Confirmation is also cheaper .
Happy non-Apocalypse to all !