Toyota Service Plan is a ****

So my car goes to service and comes back feeling not much different. They did not change spark plugs. I called and emailed with no response. I have never know a service to come without change of spark plugs…what is the point of a service if one cannot feel the power difference on one’s vehicle. Iva asked and emailed and nobody is giving me an explaination that makes sense. It is clear that services done as part of the service plan is a ****!