How much will it cost to fix my home button?

A while ago i tried to glue something onto the home button of my iphone 4s. Yes. I understand that was stupid but there's nothing i can do about it now. Anyways i pressed the button down when the glue was wet and the button got stuck down. I used a needle to scrape the glue off but the botton was never fully fixed. Overtime its become completely stuck down all the time. It makes siri come on, and make noise during school And my phone is always exiting out of my apps and facetiming ppl. Its So annoying. And i have to explain to everyone not to press the button. Overall its and EXTREME annoyance. I get more frustrated everyday. Everyone says i shud just go to apple and get it fixed cuz it'll be cheap. What would need to be done to fix the button? How much will it cost? Is there any chance they would just give me a new phone alltogether for free? Probly not but i just want to know before i go. And please only answer if you know wht your talking about. Haha i don't want false info.

That was really dumb