Gst number cancellation

Come under IGST under 20 lacs so nil liability under act as per October 2017 notification .Have applied for online cancellation in January but still showing pending for processing .And login is active .Raised multiple queries through my login -no reply . Have submitted complaint in that helpline portal . Reply to contact jurisdictional office . Local office says cannot help as it will be cancelled by centre or online as not assigned to them . But they say I do not have any liability from date of application of cancellation of gst number and do not need to file nil monthly return even . Please guide on this