We have an absolute zero tolerance policy in place in regards to Denial of Service attacks on our servers, as such you have been suspected of it on two different occasions. If it really isn't you it's certainly possible for it to be someone related to your group.
Being unable to make a distinction whether it is you or someone in your group I am going to take the safe route and just do a permanent ban.
If it truly isn't you, speak with coolzeldad, this is a matter for his hands as I have no way of helping you back up your case.