It's even simpler. A strictly increasing series will always have element n be higher than the average between any element<n and element n.
Or in other words, if the number of calls is increasing every day, it will always be above average no matter the window used. If you use slightly larger windows you can even have some local decreases and have it still be true, as long as the overall trend is increasing (which you've demonstrated the extreme case of).
Same. I had PayPal do an automated charge back because their system thought I was doing something fraudulent when I wasn't. Steam blocked my account.
Talking to support and re-buying said game did fix the issue for me.