Sallie Mae makes it difficult to apply my extra payments against the highest interest loan. I have complied with their rule to send instructions with each payment. I send a separate piece of paper with instructions on how I want my payment applied but now they are not following my instructions. Their toll free customer service line puts you into a recording that does not give you the option to speak about billing problems. I only got an alternate contact number by choosing the option to apply for a new loan. The new contact number is only open from XXXX - XXXX. I feel that Sallie Mae is playing games so that people will give up on having extra payments applied to the higher interest loans.