They say one to two billing cycles it will appear on your statement. However, that doesn't mean the money is not back in your account. For example, if your statement prints on the 8th and the credit is done on the 9th, then it will not appear until your next billing statement. Hence the phrase two billing cycles.
Like Regina said, it should be on your account within 7-10 business days, if not, give them a call. But if you are just looking at a billing statement that comes in the mail, you may wish to check with your credit card company to see if it will be coming in the next statement.
...worked for a credit card company for a few years...