You stated you are having reno's done, not just the kitchen. Therefore the contract will have a clause re demolishing and removal, in general. It may not specifically refer to the kitchen.
It is not unusual for builders to take the old stuff, and often a lot of it gets smashed anyway. People that want to get a kitchen / bathroom out in one piece to re-sell will often organise to do the strip out themselves so they can take their time and do it carefully