I agree, at 2.4M/year, i'm surprised you don't get more. we spend about 150k/month on Azure services, and it seems like we get a lot more service and roadmap influence....
In my experience a lot of it comes down to how effective their account team is. A good one will communicate with and work to influence the product management at AWS and set up meetings to discuss things as necessary. A bad one can get feedback from the customers they are assigned to and never do anything with it, or send off an email and never follow up.