if I purchased a product in may,17 with 5% vat and now in July I returned this material after implemention of gst .now gst rate on this product is 12%. how can I returned it dealer. 
taxable value 100
add vat  @  5 %.    
 total bill value         105 
now return value is 112(100+12)
            
             
			 
               
			 
               
							