Put it in writing to them as others have said stating that you can smell gas. Also, tell them that you want it in writing that they are responsible if someone gets hurt by their property that they refuse to pick up, that should get some movement but at the same time call the township you live in because they don't want your neighbors calling or any potential liability as well as your county board of health. If you do those things, I doubt this will last to the weekend. It's much easier to F off a customer than any government entity that can possibly affect your ability to do business there. Good luck!