I called the company and asked if it was possible for them to come out and only refill one of the tanks, since my husband and I could not afford to pay for both to be filled, and we don't use that much propane anyways. They said it would be no problem.
When the propane truck showed up, my husband spoke to the driver in person, and confirmed that he would only fill one tank.
Surprise Surprise though, he filled both anyways! The propane company is 'sorry' and admit it was their mistake, but we still have to pay them an extra $360.