var value is a factory is automatically reset to its original value

I have a factory in which I have declared a var which is being returned through a function. I am assigning an initial value to the var.

This function has a binding to a variable in a controller.

I also have another function in the factory through which I am changing the value of the var.

The problem is that the var rests to the original value, even after its value is changed through the second function.

Any ideas what is going on ?

Thanks, Murtaza