Where's the Oil Tank?

Well, after scheduling a special contractor to come and remove the oil tank from our basement (and file the permit paperwork, etc), we swung by the house today to find the oil tank ... GONE! The general contractor's guys had removed the tank. Not good. Since the original guy had already filed for a permit with town, this could get ugly. We called GC, and he left a message back saying, basically, that he did us a favor and saved us some money.

But, I also spoke over the weekend with a friend (whi also happens to be our current landlord in our temporary house). He said that we should absolutely get a signed letter stating who took the tank out and where the tank and the remaining oil went. He said we could need this if we ever go to sell the house.