At the bottom of the list you will find a "Paid options" section. The author says they personally have had a good experience with DeleteMe and Kanary.
I assume they wouldn't just "undo" their opt-outs?
I'd prefer a one-time payment over that darn subscription-recurring-revenue-model.
(I've been working for one of the aforementioned—Kanary—for about a year now on this sort of thing.)
Re: undoing opt-outs, we do not do that, but data brokers will re-surface your information again if they find it elsewhere.