What a PIA for all of those who have been caught by this stupid accounting problem on THEIR end, not ours.
I'll just put out here how i keep track of my miles ... a lesson learned a looong time ago when i had to chase down a significant amount. I go into my transactions and pull up the entire year and then hit the "print this page" button and toggle my printer destination to "save as PDF" & plunk it down on my desktop. Whenever there is a change in my account i pull up that document and cross off items that have posted properly. This gives me a hard-ish copy of my account that i can refer to when needed. I do this at the end of every month. I also keep every single receipt that enters this house (including those stupid dollar store ones!) so that i can stay on top of the budget -- the AM related ones stay on my desk until they post. Any AM related e-mail go into my AM folder edited with comments if they pertain to miles that will post later, separate folder to stick my on-line shopping e-mails, flagged for the last date they have to credit the miles. If there are ever any booklet/flyer/coupons i make sure to grab extras for proof. I have a bookmark folder where i save all the webpages with the FAQs & Terms & Conditions -- they remain active forever it seems! -- and i take screen shots of the offers that change regularly. AND a big help lately is the fact that i use a distinctive font when posting on the DISboards so i can easily search for any of my posts!
AS with anything you read on Social Media take this post and do with it as you will, YMMV. You may find it a tad (or more than even!) obsessive but it has saved me on more than one occasion. Those miles are hard to come by so i track them with care!