In 2000 I obtained a student loan. I defaulted in 2001. I have recently been contacted by a collection agency threatening to sue. Do I fall into the statute barred category or do I have to repay this loan. I did pay back the government portion as they took my GST and taxes. This debt is payable to the bank.

Are you in the US, or some other country? I ask this because I'm not sure what you mean by "GST", and I'm not aware of a statute-barred category of student loans.

None of these (https://en.wikipedia.org/wiki/GST)seem to fit.