Can CST purchases be shown in VAT returns??

HOW TO REVISE CST RETURN, ONLINE

IS THERE ANY CHANCE TO FILE CST REVISE RETURN

CST Purchase Return Shows as CST Sales in Return Filling at that time.

& Also Colllected CST 2% Tax on Such Purchase Return on which generally Tax is not Collected.

And also CST C Form Mention at the time of Filling of Return.

In Assessment, Department Demanded 3% Tax on Such Due To Non Availability of C Form. along with Interest & Penalty.

Give Your Valuable Guidance on Such Matter as well as if possible, then suggest Case Law For that.