Check with your local store as this kind of thing is at Managers discretion.
For a fast moving device, I can't see it being a problem as they could easily sell it to someone else if you didn't go back for it.
More obscure phones might be different though but for the OP6 it shouldn't be a problem.
I have no affiliation whatsoever with O2 or any subsidiary companies. Comments posted are entirely of my own opinion. This is not Customer Service so we are unable to help with account specific issues.
Please select the post that helped you best and mark as the solution. This helps other members in resolving their issues faster. Thank you.