Is it possible you have, perhaps inadvertently, created two different accounts over the years, and the account you are logging into on your new device isn't the same account you made the transactions from? You have to eliminate all possibilities.
I've thought about this but I can't find anything in any of my other email accounts, all coinbase activity is restricted to one single account.
And I have confirmation emails around the setting up of the account, but I never had any emails that mentioned the deposit or the one transaction I completed. They only simply mention the creation of the account.
By starting this thread I'd hoped to maybe gain an idea of how to contact a real person there. So far my efforts to open up a case on this issue have accomplished exactly squat.
edit: Oh!! I did find something in another account! I may have addresses for blockexplorer, I have some emails to read.
edit again: found 'em -- it was another obscure email address that I rarely use. I feel like an idiot but at least I found them.
Thanks!