Can my private student loan go into default during my Chap 13 case?

I have private student loans (were not in default at the time) that I included in my Chap 13 (filed 07/31/08) & was told, which I understand, that they will not be discharged. After my case was discharged(April 2012) I received a letter from Wells Fargo stating my loan was in default and the total balance was due. When I called to verify I was told that it went into default in April 2009, but I can discuss a payment plan. When I told the rep that I was in a Chap 13 she said they knew that, but the trustee''s payments weren''t enough. The rep said that student loans aren''t included in the automatic stay/court order. Aren''t they violating the law by doing this? My understanding is that the court order has to be followed by all creditors, including student loan lenders .