I've cancelled various subscriptions through Microsoft probably 10 times over the last 15 years and never had any issues. In fact my experience is often that the bigger the company the easier it is to cancel things or get a refund. Hell Amazon has on multiple occasions just sent me money for something I wanted to return and told me to not bother even returning it.

Obviously I'm not defending megacorporations - they're fundamentally incompatible with a moral society, but of my many complaints with them, "Their products don't work" or "Their customer service is subpar" is almost never one of them.