HiCustomer Thank you for coming to Just Answer for help with your question. If the IRS says that they sent money to your bank on May 15, then you need to deal with your bank. Find a copy of your 2007 tax return. The bottom of the page on a 1040EZ, or the bottom of the 2nd page of your 1040A or 1040 has the account information that your refund was sent to. If the direct deposit on your refund worked, then go to the bank and have them check their records for the rebate. Show the numbers on your tax return to them and have them double-check that those are the correct numbers for your account. Sometimes, banks delay an electronic transfer, but if the IRS sent it May 15, then the money should have been credited to your account by now. Print the e-mail from the IRS and show it to the people at your bank. Make sure that the bank hasn't made a mistake.
If the numbers are all correct and you received your federal tax refund okay, then call the IRS at 1-800-829-1040 and pick the menu options to get to a live agent. You may have to wait a long time because the IRS is extremely busy right now.
If your federal tax refund went astray, then your rebate has gone the same way. Whatever you did to find your federal refund, repeat to find your rebate.
Sorry I can't give you a more specific answer. All I can tell you is work with your bank first, your tax preparer (if you have one) second and the IRS third. Good luck and hopefully the bank has just been slow to post the money to your account.