GOODS RETURN with Credit note

Deebond Pune (2 Points)

27 March 2021  

Dear sir, 
i am seeking for the pending payment since june 2020 from one of my Dealer. As last bill was genrated in may 2020 and as per some GST clause i cant issue a Credit note after sep 2020 so i gave him option to return goods(aluminium Composite sheets worth Rs 138000 out of total pending account ledger of Rs 245000) in order to settle my account.
now as i cant issue a credit note only option left is that if he SALE ME BACK material worth Rs 138000/- so that our actual pending payment liability become less and can be sorted out in few days.
Just want to know how can i proceed with this option and if client has any loss while making sale to me in view of GST regime.

kindly enlighten