Cancel of gst number notice received

A GST-registered dealer cancelled their GST number and filed their final return. However, they've recently received a notice from the GST department regarding excess Input Tax Credit (ITC) claims from previous years, specifically a difference between GSTR-3B and GSTR-2A. The query is whether they must pay the disputed amount even after cancelling their GST number. The advice is to reply to the notice first, and payment with interest may be required if the reply is not satisfactory or if it was a genuine error.