Rebate / refund on Sodastream gas cylinders?

WLITC

Hi all, wasn’t sure where to post this. I have a Sodastream that I don’t really use so I was going to sell it or give it away. I have quite a few gas cylinders, I know you can save £10 if your exchange them for new at the likes of Asda or Argos, but can you just get a refund for the £10 without buying a new one? I’ll keep one full one to go with the machine but was hoping to claw back some of the cost of the others if I can get a rebate or refund? 

saveallmymoney

You can sell them on eBay, i've bought spare ones from there before.