You can buy the LEGO Star Wars: The Force Awakens 3DS Game from Argos with the special offer of getting a free BB8 drawstring bag.
"Buy this Lego Star Wars game and get a Free BB8 drawstring bag. Offer ends 22/01/2017."
Same day delivery is £3.95 or collect in store for free.
If you want a closer look at the bag, have a look at this product and click on the photos on the left hand side: http://www.argos.co.uk/static/Product/partNumber/5311457.htm