Did you purchase LR 5 as a standalone program or as part of a Creative Cloud bundle?
Do you mean July 28 or actually January 28, which is 6 months ago?
Is the purchase listed on your account?
I purchased it alone on January 28th of this year. It is not listed under my Adobe account. Actually, nothing is?
If there is really nothing listed under your Products or your Orders or whatever the page sections are called, now, then I'd suggest you talk to Adobe, directly via Chat, which you can get to by starting on the Contact Us page and then indicating what products, problem area and problem you're having: http://helpx.adobe.com/contact.html
You do have to have purchased the products using the same AdobeID (e-mail) as you're logged into Adobe with when trying to view the orders and products.