I was also facing the same issues even I tried all the solutions mentioned here & some other solution except stopping or pausing the server.

I used another trick for it.

1. Query the sysprocessess

2. You will receive the same message stating "Changes to the state or options of database 'test' cannot be made at this time. bla..bla..bla"

3. Check the resultset, get the highest spid from the result. add "1" value to it. say if you got spid as 75 you have to kill the spid 76.

4. Your whole & sole connection to database is killed now.

5. use "Alter database [MyDatabase] set multi_user with rollback immediate"