Problems downloading software from the Apple Store

Has anyone had a problem with Mac App Store for the download of purchased software? Three times they have sent an email with a license number and password (different each time) but the email with the PDF file attachment containing the redeemable contents never makes it to my inbox. I use gmail and allow spam to go to my inbox. Both Apple addresses are in my address book. I have spent close to 3 hours on the phone with support and have gone through a number of searches at their request to find the missing email but still nothing. It seems ridiculous to me that so much security is placed on the download of older operating systems like Lion v7.0 which is what I bought as the maximum upgrade I can put on my early 2007 iMac.