Search Functionality needs improving

We have had numerous tickets open for our search function on our website as customers can not find what they are after using our search, it is no customization, no optimization or alternative settings that would allow it to be configured for our needs. All it has is a simply "&" function and does not search another other way and that has never been good enough for the complexity of our site. We need users to have relevant results returned for their searches. Instead most of our users give up and do not use the search function as they can not drill down and find what they are after. This is a 2 part problem as it can not retrieve some product data below the parent level due to our website structure. Improved search-ability, increased satisfaction from our customers, more sales, increasing confidence in our search function to build trust that a user can do complex and simple searches which ultimately leads to finding what they are looking for when visiting out website f1moto.com.au