The same thing happened to me as detailed in many other compaints. Getty seems to target small businesses with strongarm legal tactics to collect funds for unintentional, unforseen, and often poorly substatiated copyright infringment. Avoid at all costs! Beware when using "free clip art" off any site, even if it doesn't have the "Getty" name associated with it. The fine print says that you need a license for "commercial" use, i.e. if you sell anything on your website.
Then Getty uses software and paid"finders" to track you down and send you a bill for "royalties" and "damages". A similar picture that would have cost you about $10 on shutterstock, could run you $600-$900 or more. Apparently, this is a totally legal business model, but in my opinion, it's very deceptive and predatory. Getty has had over 100 complaints for similar practices and a C- rating from the BBB.