It should be possible, but you need to contact the store.
I did twice but they don't help.
Don't help = not reply? Just wait, they will ger back to you.
They did reply saying they are waiting for confirmation on this, but no email ever since. But I may be too impatient.
Do you think it would be better to buy the Hold the door one now and ask for a refund of the other one then? I'm just afraid it solds out or something. :'D