Check your delivery ticket to ensure that the amount of gallons delivered was mechanically printed on the ticket. Many states do not allow the gallonage amount to be handwritten, it must be mechanically printed on the ticket. Also, be sure to retain all your delivery slips and check to make sure the price per gallon appears on the ticket at time of delivery.
Warm vinegar will generally soften the most stubborn old glue on old furniture. Dipping the parts to be reglued in warm water, and then letting them dry out completely, will help to open up the wood pores and allow the new glue to enter the wood more freely. Warming the parts on top of a heater or in the sun will also help open up the pores of the old wood before regluing.