First of all,

the limits are not there to annoy you and not to make you buy the premium version. The limits are there in the way they exist because of the users.
As a user, would you want to get spammed? Probably not.
This bot was not invented for spamming but for users to enjoy the server through active chats. And thats why the limits are there, to prevent spam.

Bla Bla.. How to increase them though?

There is actually a way to increase the limits. This is only available for servers that really need it, for example huge servers with more than 10 main channels.
How to? - Contact us by joining the support server or emailing us at including a description of why exactly you think you need it and an invitation to your server. An increase of the limits will then be considered and you will be notified.