99% of the time you can stop this stuff from your .htaccess file. not sure if you are using one or not. Be careful with it as you can screw up the site if not set up correctly. Heres a link to an online generator. http://cooletips.de/htaccess/
Now if it was me and I knew where the bad traffic or bot was comming from I would create a blank page to redirect them to or just redirect them to nothing. I to was getting some spam on my contact form but in the end I removed it as I decided it was better to have the customer contact me by phone and I can work the sales that way. I was getting maybe 1% of my traffic using the form and felt it was just not worth the headache.
Another thing to look out for is do not have your email in any of the website at all. Even if it can not be seen on site but is residing inside your code someplace the bot will pick it up. This is one reason why you see seasoned online vets posting their email as webmaster [at] site.com
Heres some small code as an example I got from
Sad but true: There often comes a time when the "open" nature of internet becomes a problem. This can be by accident (a badly behaving robot) or on purpose (someone attacking a banner network). In either case, the first level response is the same: block access with your .htacccess file :-).
This isn't meant to be a full fledged tutorial, but a quick example of the more common needs.
The most common scenario is where you want everyone except a few visitors to be able to get to your site. Your .htaccess file would start like this:
order allow,deny allow from allThen you follow that with lines to specify the addresses that you want to block:
deny from 192.168.128.14 deny from 192.168.128. deny from somehost.example.com deny from .example.com Hope this helps.. Jugg.
BTW an .htaccess file is just a simple text file with all this type of information in it, that gets read by your browser when it comes to the site and gets read by bots. Open notepad copy and paste this info in there and save the file as .htaccess. NO NAME just the extenion as it reads. Take that file and place it in the root directory of your webpage. The same place your index file resides. Do not place it in the images folder or anything like that or it will not work. It must be in the root/main directory.