You can appeal an Adense ban. I highly recommend using Google's tow services:
Google Webmaster's Console :
https://www.google.com/webmasters/tools/
Google Analytics :
Google Analytics
Both are *essential* tools if you are running a site that's monetized by Adsense. First off, the Webmaster's Console is your ticket to communicating with Google about possible click fraud or somebody trying to mess with your Adsense account. If you use Analytics, you can see where your hits are coming from and it's your obligation to report potential problems to Google. I have heard of many people being banned by AdSense in the past, but after reading Google Employee Matt Cutt's blog I've learned that using Adsense is a responsibility, not a luxury and that you as the publisher must strive to show that you're watching your own traffic for possible problematic issues.
Think of AdSense as a real business. There have been many people who were accidentally banned for clicking on their own AdSense links, or the more likely story is parents who run a website having their children, family members, friends, etc clicking on ads thinking they are helping you out but when the analysis is done on Google's end, they can't discern that 100 clicks from the same IP address that is logging into your AdSense manager might be a son or daughter or friend who is trying to help out with good intentions, unknowingly causing your account harm. In the case of fraudulent clicks from a competitor or an enemy, Google has been doing a much better job of tracking offenders and tracking proxies, banned IP's etc. As with anything, never give up so easily and make an effort to reconcile the problems.
Yes, AdBrite is one of the best alternatives to Adsense but again, an AdSense account is a responsibility.