GSTR1

manju (Going to be CA soon.....)   (92 Points)

21 May 2018  
I have received Advance for the month and i have paid the tax on the davances received. and shown that adavances as advance received in GSTR1. afterwards the adavance have been returned to customer. now i have to show that in GSTR1. where can i show that.
(Remember it is not a sale just advance tax liability and no invoice is raised)