A request to all cell phone users (my rant for the day)

I can excuse annoyances such as loud conversations (cell phone or in person), loud music, barking dogs, and such if when politely asked "excuse me, can you please keep it down" the offending party responds with "oh sorry, I didn't realize..." . But, unfortunately these days the response is "too bad*, its your problem not mine and I'll do as I please" then get even louder! Makes me feel like breaking out the polka music and cranking it up!