HSN CODE 520100

hai gd afternoon,
actually I sold cotton (HSN CODE 520100) 100Kgs @ Rs 150/- per kg to Buyer of Rs 15000/- (Including Tax), after received goods and buyer weighted cotton in his premises only gets 90 kgs. 10 kgs weight shortage getting and informed to the seller and accepted to raise credit note for 10 kgs cotton shortage, actually this is getting likely depend upon weather. while going to raise credit note by the seller created one ledger as shortage expenses and what is to be mention HSN code of shortage expenses, actually my turnover is more than 20 crores, so HSN is mandatory, what is HSN code of Shortage expenses ledger, is shortage expenses ledger consider as Goods Or Services, please suggest.