Check if URL entered in browser is correct and if not redirect

Hello

I'm not sure if this is in the correct forum so apologies if not. This is the issue we are having so any help gratefully received. This is an example:

We have a website 'www.ourwebsite.com' on IP 111.222.333.444

We have had instances where other sites (completely unrelated to to ours), for instance 'www.unrelated.com' are resolving to ours 'www.ourwebsite.com'.

When checking on MXToolbox, the site 'www.unrelated.com' is pointing to our site 'wwwourwebsite.com' IP 111.222.333.444

So, is there anyway to check the URL someone enters in their browser and if it doesn't match 'www.ourwebsite.com' it redirects away from our site?

I hope this is clear! Thanks