An easy way to make your site more secure
If you are having trouble with phony orders being placed or spam comments appearing on your website, a good place to start is to restrict access from countries you don't do business with.
Depending on how your site is setup, you might have a log of the IP addresses from the offenders. Use one of the free online tools to see where these IP's are located.
If your business has international customers and you find that most issues come from just a few countries you don't do business with, then you should probably deny access to only the problem countries.
If you only do business in your home country (or a limited amount of countries) you should only allow access from those countries.
There are many different setups for web servers. Most likely your site is using either Apache or Nginx. Speak to the person that manages your website, it should be quite easy to put the blocks in place by updating a text file on your webs server.
You can get this list from a service like IP2Location
IP addresses get reassigned constantly. Keep an up-to-date list to avoid blocking potential customers.