CW California, I don't think you can make a payment at a local branch, although I have never asked. When I called in after my online account had been disabled back in April the CSR told me he couldn't accept my payment by phone that I would have to Western Union the payment. It was the 15th of April and I didn't want to pay a late fee. I asked him to please accept the payment. He looked into my account a little further and saw I was tagged with NACA. He transferred me to the advocacy department and they took my payment over the phone for $12.
I have read that once your file is being reviewed for a mod that the payments are put into a suspense account. My file was submitted to
CW on 2-28, online account disabled beginning of April, April and May payments both made by phone AND APPLIED to my balance.