Website Security & Vulnerability Assessment

We've noticed security issues on our website. www.plaxsys.com. We recently I've noticed some unrecognized charges and payment on my Stripe.com account report (see attached) and now we've started receiving call from people saying that their credit cards were charged for products and services that do not exist on our website. We will like a site Vulnerability Assessment done and recommendations on how stop these fraudulent activities and strengthen our website security.