My C5 website has 5 forms but the reports section shows about 10 forms, i.e. it shows each form more than once because I changed the name of the forms a couple times.

I thought that deleting the old page versions that contained the forms with old names would solve this problem but no luck. I also re-run the indexer and sitemap generator after deleting the old versions, still no luck.

Weirdly enough only one of the forms offers the "delete unused form" option.

When i click "open page" beside one of the old, non-existent forms it just takes me to the homepage.

So how to remove them?
screenshot attached