Economy Lube

My husband had an oil change and undercoating late October. January, our vehicle broke down on his way home from work. He had the vehicle towed to our Hyundai dealer ship. Hyundai contacted him the following day stating the oil cap had fallen out, therefore all the oil drained and ceased the engine. Our receipt has no date or mileage recorded for our next oil change and no sticker was put in the windshield. This is over $9000 repair cost to us. He has attempted to contact economy lubes office with no success as they are ignoring his emails and phone call. We are seeking legal counsel to recover all costs.