Any proceedings suspended on your request you can reopen anytime by submitting a request to reopen proceedings. It doesn't require any special justification. All you have to do is write that the suspended proceedings can be taken up again. Do remember to let us know if there are any changes to your address. You have 3 years to request to reopen your case, counted from the suspension date. After that, we shall assume, that you do withdraw your application altogether and your case will be closed.