was returned to Navient as the loan provider

I had a student loan which had just gotten out of default status and was returned to Navient as the loan provider. Three times, during the month of October, I had submitted payments totalling $944.88. Last week, I checked in to make another payment only to find the loans had been changed. Shortly after I received notice that my loans had been consolidated. The original loans that I had already paid on no longer exist, the previous loan was at 3.19% while the new loan is at 3.25%, and those payments I had already made were not added on to the new loans. Granted that I was rather upset, and my query was was laced with excessive vulgarity, however, I was informed that it would take 30-45 days to apply the previous payments to the new loan. Which is completely unacceptable to me. When I told them I wanted the amount applied immediately, the response was to contact the Department of Education. Which is stupid all around, since I can still make payments to the new loans through Sallie Mae‘s website, and the Department of Education has not contacted me at all about the loans, AND it is Sallie Mae that is holding onto my previous payments which is forcing me to pay more on the loan since I’m accruing interest on a loan that has reset to the amount when they first took over the loan only at a higher interest rate. I was set to pay this thing off and be done with it completely by the end of this year. Thanks to Sallie Mae “consolidating” my loan and refusing to include payments already made, AND refusing to apply those payments in a timely fashion, I am most likely going to be stuck with this thing for another month or two into next year. Which, of course, means I am going to pay more than I should have.