How to deal with a host that won't stop summoning?

Today, in one invasion, I took out 11 phantoms while seeded. I could not kill the host. I was eventually overwhelmed by the 12th, 13th, and 14th despite regaining Estus and having a blessed/sun princess setup. To be clear, the host set out to gank the area and was not interested in PvE.

While I love longer PvP scenarios, ones where each side is locked in stalemate, it eventually gets to the point of absurdity. After the 5th or so parry->1HKO, he spent the entire time trying to avoid me and summon whenever possible.

I'm not trying to be harsh, but I don't think I came up against many experienced players. The stalemate occurred because I'm at a relatively higher threshold of skill, while they simply have numbers that are heavily skewed in their favor. That's what's frustrating about it. Anyone else think From went a bit overboard protecting new players? And what ways (if any) do you deal with infinite summoning in a scenario like this?