[pdimitar]

> When you reject people, they really really want to dig in, know why and then refute or try to overturn that.

That is 101% true. However, when you give feedback you can also politely say that it is not open for a debate.

"We found you lacking in X, Y and Z. We are not interested in advancing our communication. All the best and goodbye."

So IMO just give feedback once and never reply again. If somebody is persistent, block them. Then you would in your full right.

Being fully silent without a single message however is not okay.