Heating oil Leak in my basement- please Advise

i signed on with a new oil delivery company this year for oil deliveries and on their first shipment filling the tank it cracked or blew something and left about 10 gallons of oil or more on the cement area under the tank. They claim its not due to their negligence as they heard the whistle blow when filling and stopped. also the tank was not the original tank but over 15 years old and was not inspected by the new oil company when the contract was signed with them, only the furnace . the oil tank had a full tank of oil in it during all summer of 2012 and just this nov 30 became empty requiring our first actual oil delivery. There was no leakage before that time. The oil company was called back to see the damage and they said they spotted a hole under the belly of the tank and placed a magnet type plug over it. The tank was pumped and a temp tank outside the house hooked up. The fire marshall was called and gave the violation . i called my insurance company pronto within two hours, and they recommended a company that is owned by a franchise.
They came about four hours later and only sealed off the furnace tank door entry and set up fans. I think they may be waiting for the claim adjuster that is planned to come tomorrow? As they mentioned something to the effect this may not be covered by my insurance? They said they would come back the next day around 9:30 to remove the oil which is now lingering on the surface of the concrete slab basement floor. i am currently in another state and my 25 yo son had to deal with the situation and let them go without nothing done! From the photos the damage looks huge in the amount of spill. I put in a call to the cleanup Hazard company but no response yet on their overnite emergency line. My son is staying at a friends house for the nite. I am extremely worried about the company hired to do the job over the phone as there seems to be no urgency? How long does this oil take to seap through basement concrete into the soil or under my house foundation? it seems to have stayed in a 3X 5 feet area directly around the tank. But i'm not there to see! Any professional advice please. My son took before photos and greatly worried till I can reach a human contact by phone tomorrow .