Xbox 360 email account hacked.

[bigbadblue05]

Guys,this has been a bit of a nightmare trying to sort this out but the story goes like this,my sons friends on xbox live started receiving abussive txt messages from my son and i got them myself but they were not even sent from him it was a former so called friend that has now left his school and moved away and he even admitted who he was to another kid during a message, thats the mentality of this 11 year old lol,so straight away i think its hacked,so i go through all the steps that microsoft tell you to do, he was also blocked by these kids ages ago for threatening some of them with account hacking,i changed the passwords,added more passwords,checked to see if his profile was on any other consoles which it wasn't so microsoft recommended deleting his profile then downloading it again from live to the one and only machine he has along with the new passwords for everything and extra security settings added and a new password on the email account too which got done first,i done this from my laptop that has never been used in his house,later that night the abuse started again to these other kids and one of there mothers reported it to microsoft and gave them the wee guys real profile name,this was still going on today and he could even hear any messages on chat that was been spoken between my son and my nephew who also had him blocked,i told this wee guy whom was doing all this sh*t to chuck it and then i got more abuse lol ,then i get a message from him tonight through my sons profile who he was still sending them through with appoliges saying it won't happen again and my son got one from him through this kids own profile, saying he was sorry even though he is blocked and not a friend,my question is how did this kid still manage to do this even when everything was changed and secured after a fresh profile download?,nothing else in his account was changed by this wee guy just txt's and chat he was sending and listening into,it has me stumped,Any ideas folks?, just incase he decides to come back.
cheers