Misrepresentation

I have a service plan with Absa (Innovation group). My car is due for service but when we lodge a claim, their Agents advised that they can't cover for replacement of plugs. I really don't know what kind of service one can make without replacement of plugs. This is pure misrepresentation and *****. What they sell is not what one gets. I'm really surprised and unhappy. I think I should cancel all my policies before I get disappointed further.