I moved from a low tech tank to high tech around labor day and QUICKLY got infested by pond and bladder snails. I'm guessing they were eggs on plants as I was quite careful rinsing stuff. I'm ok with the snails, they do a lot of cleaning, and are a natural part of such an ecosystem. I can see folks thinking them unsightly depending on tastes.
Over-feeding and/or lots of algae makes their population explode. I keep them under control with manual removal. If I think they've started to overpopulate I turkey baster 30-50 of them out, rinse repeat each day until I feel better. I put thick airline tube on end my basters so they can reach and also press/seal against the glass (due to being soft). It takes all but 5-10 minutes to get out many more than you think you could.
But they breed fast. I have shrimp, so no chemical options (probably would not do that anyway).
There are lots of clever traps that you can do to speed it up.
As far as eating your plants. I have never seen snails damage healthy plants, and I have always had a large snail load. Actually I don't see them damaging unhealthy plants. They do take out dying and decaying plants, that died of other causes (melted, failed to thrive, damaged, ...). And I'm happy they do! While I keep my tanks tidy, they aren't squeaky clean like other folks. So I don't have the experience of what happens if they have no food source at all, if that is even possible. There is always biofilm for them to eat, on everything, and a lack of food would cause them to breed at a very low rate so they wouldn't turn into a large plant murdering hoard.
You may want to re-eval to see if maybe the s.repens could have been dying from other causes.
I'm going to watch this thread as I would like to know what other people do to remove them.