You seriously need to check with student finance about the old fee system, not your actual university. I enquired about changing courses with my university, they told me it was possible and I could stay on the old fees, I went for the interview, got a place on the course - everything was finally coming together. But then I rang student finance and was told "No, we can't do that. You'll be on the £9000 a year fees. It doesn't matter if you're at the same university."