Weird, if your loans were transferred you should have received an letter before it even happens letting you know where it was being transferred to. In my case it was to MOHELA, and I received an letter from both parties a few months prior regarding the change.
Anyways, just finished paying off my loans this month, and it's a big relief. Good luck!
I just got my letters saying it was switched yesterday, well after the fact.
Glad I have it figured out, not pleased with how it came about though as they kind of leave you in the dark.