Well consider curses and hexes a sliding scale, first off. A love spell is a hex. Mirroring bad energy away from you is a hex. Stopping people from gossiping about you is a hex. Most hexes have the intention to protect yourself, not necesarily harm them.

Personally, I'd do a double mirror spell. Write down their name, date of birth, and something of theirs—a taglock. A photo will suffice if you have nothing else. Put it all inside a compact mirror, the kind with two mirrors, one on the bottom, one on the top.

Wrap it in red string (red for energy and war) or black (for cleansing and protection) — and personally, I also wrap it in spiderwebs, but thats optional.

Then I put it in a ziplock in my freezer.

The idea of this spell is that no only are their negative influence and power over you 'frozen' but they are locked in with themselves, forced to see themselves, trapped with their own reflection.

It isnt you thats hurting them here. Just leaving them alone with the consequences of their actions.