When you negotiate a mortgage, you have to decide whether it will be at a fixed rate or at a variable rate. When organizations have opted to have a fixed-rate mortgage, they have made a choice. In this case, the interest rates were lower than the market rates. So if they wish to change the mortgage and the conditions, they have to wait until the mortgage expires. The same thing applies for a mortgage on your house. You have to make a choice or pay a penalty, if you wish to make a change. At that point in time, the rates were really very favourable.
On May 30th, 2012. See this statement in context.