Hey Holiday, if you want to remove them....block each one first under options....then goto "block list" above "players met" and when you goto options it will give you that option to "delete from blocked list" from your PS3......it might take abit but there's your answer.
P.S you might have to repeat the delete process on each one between 1-5 times....i was gettin errors...but eventually it will work. Hope that helps you or anyone else.
Or you can just reset to factory settings. I think there is more that one kind of reset perhaps you need to do a stronger one than the one you did. The one that wipes your hard drive and reformats is one I have used. That does it for sure!