A good rule of thumb as you shop is to assume that any major purchase will have to be returned. If you don't know the return policy, ask a salesperson, and don't buy the item until you're satisfied with the answer. Return issues become even more complicated as Internet commerce continues to grow. It's important to understand even the most minor issues that could apply to your purchase. If it's important to you, get it in writing.
Oral promises are very difficult to prove.
Get it in writing that they'll be provided at no charge. Have it written on the paperwork. Make sure it's on the estimate and your contract. Today's complicated business world revolves around contracts and the written word, not a promise and a handshake, so protect yourself. Even with the best intentions, a salesperson may not remember or may not be employed by the same merchant when you remind them of a promised service.