Hello,
Nope, never happened to me.
However, I don't use these "diversity packages" that are being sold here. I have seen links from two diversity packages and they were all cheap, spammy, crap. If you bought those type of links, then it most likely did more damage than good. You get diversified anchor text ratio in exchange for a dirty link profile. 100 links for 5 dollar, surely it will be of no help.
When I want to diversify my anchor texts, then I just buy links from "normal vendors" who I know have quality stuff. Low quality links will destoy your site no matter if you bought them for diversity purposes or to boost rankings.
If your rankings used to be stable for a long period of time, and then suddenly disappeared from SERP after you received these links - then I would ask the seller to delete the links. If the bad rankings continue with no improvement, then I would try disavow file.
*EDIT* But of course, follow what naskootbg said before messing with disavow file.