The best advice in this instance is to ignore this. Your loan can be taken out of default for free through the Default Resolution Group
Am I notified when a Treasury Offset is about to happen with my Student loan?
A notice of intent to offset your loan will be sent to your last known address. This notice will inform you that the offset will begin in 65 days. Normally, this correspondence will only be sent once
Is there any way that I can contact the Collection Agency involved with my Student Loan?