I feel your pain, trust me I do. I forgot many a places I have ordered my stuff from about 500 times. So I started making a list...and add the discount codes too...
Understand that kanger is a multi national global corporation. Contacting them almost doesn't even seem right for this situation. As strange as that is to say, I dont call Chrysler when I have an issue with my Jeep. I just call a mechanic or the place I got it from.
Most email accounts have a search option, yahoo mail can go back years in time searching for one key word. Same with google. Perhaps you might be able to search your emails for who you got it from.
wish you the best of luck, I
my suboxes and would be sad If even one of them got the case of the dumb ass like yours seems to have