@qwerty : Unfortunate, sometimes things just don't work out as they should. But in reality, Google should be doing better on this than you are reporting. My own experience has been positive from a delivery perspective, but that might just be blind luck.
Happy holidays.
Thats a shame to hear and i understand you are frustrated!
Why could they not send the link to another email account since it seems to be some issues here?
My experience is very good with stadia customer service, always quick response on the chat, Even got refund on a game that had been played over two hours, because of an issue i had with it.
Also got Nice help to set it up since i had issues with my cromecast.
Hope you will get the help you need soon, send them an email with your story of what you have been trough!
I have told them multiple times to use alternative methods but they always ignore that and tells me to rest assure...
In addition, 24hours after i spoke with them yesterday still no update.