Lame can be read as an ableist term. Pretty simple.

I want to hand the shame back into the hands it belongs it.

As others have said, there’s nothing you say back to them that’s going to make a bully feel ashamed of themselves. They’ll change their behavior if they realize bullying is socially detrimental to themselves. If you’re alone with this person(s) don’t play along with the roasting. Keep your conversations about work or whatever. If they come at you with some bullshit, give them the ‘ol “Sure buddy” and move on.

But probably most importantly is to talk about them to other people. Tell others you think it’s weird and childish what they’re doing. Ingratiate yourself with their friends. Ask, “Why is this person doing that? What’s wrong with them?” You’re not taking the moral high ground here, you’re using social pressure to tell your bully to fuck right the hell off.