ATC will automatically terminate its provided services to you if you do something radically “out of bounds”. An example of such things might be:
- Flying while you should be taxiing
- Taxiing while you should be flying
When this happens, ATC has no ability to cope with this as it no longer follows real world flow and therefore ATC will terminate the services it provides you and will give you a dialog warning. When this happens, you can continue your flight on your own. You’re free to contact ATC again at your leisure if you wish.