Hamilton Auto Sales

Been using the services of this place every 3,000 miles since middle of 2013....paying for full service, which is supposed to include lubrication of the undercarriage. Spending near $800 now to replace joints and arms underneath that have not been greased. Manager states he will need proof its his fault, but how will I prove. Now I wonder if the oil was ever changed, or just new filter and topped off. I will never know now,,,,never returning there. Buyer beware.