Whoever you think is in the wrong here, the real takeaway is a reminder that when you use a VC-funded for-profit service, you don't "own" anything.
In either case, you are not the customer, since you are not paying them. In the absence of VC funding, however, companies are much more likely to be forced to charge their users, meaning they have a more vested interest in customer service.
There's a lot more of this kind of crap and it affects your life in a much more serious way than having your username changed.
Do you really think you 'own' your house? Might want to ask the residents of New London. Indeed when you get services like a school system for free, you are the product.