Have you tried contacting them? That would be the first thing to do.
█CirtexHostingProviding Affordable and Quality Web Hosting & Reseller Hosting since 2003 █LINUX based cPANEL/WHM Shared and Reseller Web Hosting with Fantastico █HostV VPSPremium Virtual Private Servers & Dedicated Servers powered by cPanel/WHM █We transfer your sites over quickly!I eat penguins for breakfast ...
You should look at your stats a bit closer. You should be able to see where the inbounds are coming from and what IP they are coming from. If you see a lot of hits coming from one IP try doing a trace route to see who they are.
Manipulating the stats won't do any good since they don't rely on those logs/stats pages you see. They would probably have their monitoring somewhere else. On top of that, that would be an attempt to cheat, not something I would encourage.
However, you can probably discuss with them if they ever bring it up to see if they can waive the charges or settle for a more reasonable amount example $1/GB over
I would also look into upgrading the plan immediately.
hmm, what about making a stats counter that would count up all the people that visit your site. This way you can tell if they are cheating or not, a good way to find out. Dont know though, just an idea.
Although I operate my own hosting service, I also host personal sites with other hosts. I keep a close eye on my stats checking them each morning as I make my rounds of all the sites I either own or am a member of. Besides Webalizer I also run AWStats and xTreme Tracker on all of my sites.
Although you fear bringing it to their attention, submit a support ticket requesting your current usage information. There may be a error on their side causing a mis-reporting of your webstats. It does not happen often, but it can and does happen.
As to whether a disreputable host could manipulate your stats, the answer is yes. But if that is the case, I'd not just run, but jump into the fastest mode of transportation I could find and haul my site and my tail outta there.