A screen shot would help.
Count to make sure you have 17 movable chairs. Do not put a chair in front of the manager's desk... he is already sitting in a chair. Make sure that you put the chairs on the side of the table where the keyboards are.
- Place 17 chairs.
- Pick up the Coke bottle. Give it to the guy blocking the kitchen.
- Pick up the coffee maker in the kitchen.
- Fill 6 cups of coffee. Make sure you fill the one in the room on the left.
After all tasks are done, walk towards the manager. He should step aside so you can get to the key.
If you have done all those activities with no luck, you will need to contact Support.