Your account isn't deleted (if it was, the above post would turn into 'Anonymous'). We don't delete accounts. You MAY have tripped the spam filter, but I don't see any posts hanging out there.
I am not selling access, I am selling what is rightfully mine as I purchased it and am aloud to distribute it, as per the GPL:
Right, except you're not. Look, you are not violating GPL, but you ARE violating their TOS. You're re-selling plugins which can only be gotten BY using access. What they're doing, punting you, is within their right. What you're doing, reselling their plugins, is within the rights of the GPL, but not the agreement you signed up to. They didn't make a more restrictive license, they just said 'To use THIS site, you agree NOT to do THAT.' You keep the plugin and lose access to the site, and you can still resell all you want. Nothing anti-GPL there.
You're performing theft of services, and you've upped the ante by reselling. They can, and should, ban you from their sites. I would. I'd also have an explicit statement in my TOS like 'You agree not to reproduce, duplicate, copy, sell, trade, resell, or exploit for any commercial purposes, any portion of the Service (including your membership ID), use of the Service, or access to the Service.' but I like to cover my ass.
At the end of the day, your issue is with wpmuDev. A site unrelated to this one, save they offer WordPress plugins and themes. WordPress has no control of them, no power, no ability to censure. They exist over there, like any other professional WP related site. Your only recourse is to get a lawyer, and I'm pretty sure they'd tell you that you're not gonna win.