Case Judgement on credit notes under vat act

Friends

Hope you have been come across the pratical approach as well the rejection of credit notes by sales tax officers durings assessment of all the states in india but somehow being accepted on best judgement and still, its in a dilemma..

In case of karnataka vat act; ther is no prvision of credits notes being issued except sales return (within 6 months)

here we are discussing the Credit notes considering the below practice of transferring benefits to cusotmer on ..

1. Rate differnces on account of incorrect rate on invoice

2. Volume discount and annual discount

Friends, Pls share your opinion or share some case Judgements in relating to this

your earlier in time response will be appreciable a lot

thanks in Advance