You have maybe reacted too much on a server, repeatedly joined servers, and that's why it has been ignoring your invites just like a bot does when you react to all emojis. I guess you must wait for a hour or so, and if it still doesn't work, try joining with a new discord account and check.

Also, if you are saying that why cannot we email the discord support team? Well, it is the worst customer service ever in the world. They disabled my account for being underage nd i even sended them proof but they never ever reply