Usually contracts say that the entire contract is contained within the four corners of the document and anything the salesman tells you isn’t a contract.
If there was a written contract, it might say that. I haven't always been asked to sign a written contract for appliances at retail. But even if it did, those types of contracts can not disclaim away any liability for the salesperson accurately representing the product. Verbal contracts are legally contracts whether or not the seller wants to be held liable for them.
If the contract doesn’t correspond to what the salesperson said, wouldn’t the company still be on the hook for false advertising and/or fraud?