Cst sales return in ecommerce

I think you can't claim CST if you haven't been issued C Form and CST will be charged at 5%.

Only registered dealers are eligble for the Form-C, where the rate of tax on Commodity sold is CST-5% or 14.5% if the customer is a registered dealer you can sell the product at the concessional rate of tax @ 2% against Form-C (to promote the business Govt.given this concession) otherwise to all the dealers/customer you have to charge the actual tax ie. either 5% or 14.5% of that particular product.  So if charged the full tax then you can claim the Sale Return with the Sales Tax Department at the time of filing the Return with Sale Return Credit Note.