I agree with ItsAllGoingToBeFine.
Firstly, there should be a consistent set number of warnings when people are sailing too close to the wind. Then if they cross the line something like the following could work:
Adding a divert to a page when they try to log in with either -
1)If it's for a dodgy comment and the person needs to be reviewed:
Your account has been suspended while we review it. If you have any queries then contact.....
This then should be reviewed within a stated, consistent and suitable time frame (2 working days?)
2)If it's for spam or something so so so outrageous, then:
We have removed your account for infringing site rules. If you wish to appeal then please contact....
Because just banning people without any word or reason could frankly drive some people over the edge and while mn aren't responsible for people's mental health, it's really not nice for them to end up being a direct contributor to their stresses, especially when people may have snapped and said something because they are already struggling.
The please contact us email address should not be the general contactus page, because it can feel like you are emailing into a black hole when mn get very busy. It also minimises acknowledgment that something potentially upsetting and big has been applied to a person. It should be a separate email address.
It would be much better for both users and mn I think if a consistent framework were applied.