How to make my iPhone 4 vibrate and ring?

I have a iPhone 4 and I've had it for about 3 years now. About 1 year ago I dropped it in the snow so it got water in the headphone thing but the headphones still work. For a year now my phone hasn't vibrated or ringed. It plays music, but when I get a phone call, text message or any type I notification, it stays doing nothing. I know about the ringer control, I've tried, fiddling with that but still nothing. About 9 months ago the ringer control kept flicking by itself and then it stopped working, it does look at bit dirty inside so I may need to clean it. I don't really Particulary want to go to apple but if I have no thee choose how much would it cost?

Goto settings then sounds then there will be vibrate on ring turn it on. Then put the ringer volume to highest