I myself had the same type situation when home depot reimbursed my credit card for a purchase. They could not tell me how long it would take to get my money. I did receive it by 7 business days but warning to you is the main office told me that if its a debit card the reimbursement could take up to 30 to 45 days to be returned. I was told there are different regulations on debit cards.
best of luck to you.
A billing cycle is in fact 30 days. But since the next billing cycle may end tomorrow, 2 billing cycles may be anywhere from 31-60 days from today. However, personally I have seen a credit from Walmart show up in my account within 10-15 days from their notice of refund.