Who the fuck they think they are to tell you what you're 'allowed' to do? Act like they're doing you some big favor, giving you permission. Screw off.
They never had grounds to ban. This permission assumes an authority they never had. It's like a thief who stole your car expecting you to say thank you when he brings it back. It was never yours, asshole.
I don't even like weed and don't use any other illegal drugs.