Hi Xena and welcome! You were never 'fellowshipped' in the first place so you can't be dis-fellowshipped. Lucky you! Just drift away, they have no authority over you.
If you have a grievance and like Anna Marina have a stack of intellectual weapons to fight with, then you might want to show them where they are wrong or why you can't continue but remember, brick walls are more responsive to reason than a fully committed JW is.