This "Wariina(悪[わり]いな)" changed from rough or frank "Warui-na(悪[わる]いね)"
with "kiwo-tsukawase-chatte 気[き]を遣[つか]わせちゃって" before/after in formal.
using for friends/brothers or other younger guy(s) most .
But sometimes girl/woman using ,too.(depend on own character)
Teen girl using simple "gomen/-ne!(gomeen!)[ごめん(-ね)！(ごめーん)]"
from "gomen-nasai[ごめんなさい]" (formal)
woman using "waruiwa(悪いわ)" or "waruiwa-ne(悪いわね)" usual.
This "Warui[悪い(わるい)]" means "sorry" but include
"thank" or "apologiz(not for serious most)" so not regular meaning "bad".
"-na(-ne)" is one of emphasise word instead of "very" or "really".
Also shortset "わるい/わりい(わりー/わりぃ)" only using a lot
but in this case also includes with "-na(-ne)" meaning
with intonation/face(smile or not) changing instead.
Similar phrases using more usual.
"Suman![すまん!]" from Sumanai/Sumimasen[すまない][すみません]
"Moushiwake-nee![申し訳ねぇ！]" from Moushiwake-nai[申し訳ない],
Moushiwake-arimase/-gozaimasen![申し訳有りません/ございません] (formal)
"Ookini[おおきに]" in Kansai(Kyoto,Osaka and more) area using a lot
than standard japanese "gomen/suman" and "arigatou".
This word very famous in Japan but not standard Japanese.
http://youtu.be/H7hHrmrYSGk-ben means local(regional dialect) words/accent calling "方言(hougen)".
"Katajikenai[かたじけない]" is one classic phrase still using
as Samurai[bushi:武士] phrase in manga/anime/movie/TV-dorama a lot.
http://www.tofugu.com/2008/02/09/how-to-talk-like-a-samurai/
