Long story short, I haven't. I'm wondering has anyone done it and successfully defended his funds vs Paypal chargeback dispute regarding Toribash items or tc purchase?

Ask TSA and post screenshots to prove it. Shouldn't be too hard.

I wouldn't recommend going through paypal it would probably be harder.

In my time as msquad I have never heard of someone successfully getting his money back from paypal.
The only time that happened was when the scammer agreed to return the money himself.
I always got peole reimbursed with toricredits and items, sometimes even when the scammer's acco didn't have the funds.

As long as you document everything properly you will never lose real money by being scammed.
If you believe staff handled your case wrongly post in complaints about staff because that's a serious thing.