It can take about 3 days.
Funny how you can see a charge right away, but they take their time in a refund.
I returned a pair of shoes at payless the next day (with receipt, unused).
After 3 weeks of not getting the refund, I called their headquarters.
They told me that they had 60 days to issue me a refund.
($16 pair of shoes).
So... keep track of your refunds. A check register would be a good idea.
A merchant may be counting that you "forget".