Google Photos does the same thing, aggressively prompting the user endlessly until they give in. A solution to that is disabling the malicious application and installing Google's Gallery app instead, that possesses no ransomware capability from what I've last heard of it. Make no mistake: Google and Microsoft know very well this behaviour will lead to people subscribing to services they have, for the most part, no use for. It is therefore explicitly by design, deceiving tech-illiterate people threatening to delete files they never meant to upload.