Wrong Itc Claimed

Reverse the IGST credit(if available) or make payment under the head IGST when you file your next GSTR-3B. If there is no purchase then just make the payment as stated above. 

For illustration wise details refer circular 26/2017 dated 26.12.2017. It is very helpful for all these problems. Save it in your computer for future reference.

In next month 3B you can reverse the ITC for the previous month.