With OncloudERP you can return the item to the vendor using different ways.
1. From the Item Inward Code you can raise a purchase return.
Homepage--->BUY---->Transactions---->Purchase Return---->Add new--->"From Item Inward"
2. Raising a DEBIT NOTE for the Item/stock to which the invoice generated for the purchased Order.
Below Video will help understand more on the Purchase return process of OncloudERP.