I agree with donncha.
JustHost should be willing to get sorted out. I have heard of other WordPress hsers having similar issued with "unlimited" web hosts that turn out to be not so unlimited.
Hopefully JustHost will unsuspend you and help you figure out which plugin is misbehaving. One good idea may be to disable all your plugins and check resource usage. If it doesnt drop, then dont waste your time disabling each plugin and look for a more liberal host.
I understand JustHosts position, they must ensure no single user uses up too much of the servers resources causing a slow down for other users sharing the server. Due to their low prices and "unlimited" offer they need to put more accounts on.a server to make money and can therefore only give each customer a small slice of processor/ram etc.
If the disabling of plugins doesnt work, and JustHost arent doing their utmost to help, I would suggest switching to another host.
Try somewhere like zippykid - they're wordpress fanatics, like us.
Im happy to recommend more hosts if thats the route you choose to take.
I hope you manage to figure this out with your host and dont have to switch.
Best of luck!