Technically, the 48 hours could begin the moment the letter is dated, but since you did not receive it until June 16, then you should be able to argue that you have 48 hours from when you received it.
Anyone can put any date they want onto a letter. They could have written the note on June 16th and put June 14 as the date to make you feel like you needed to get out immediately.
Where there any witnesses when the paper was dated? If not, they don't have a very strong case against you, unless you didn't get the trailer out on before June 19th. Assuming of course that the writer of the letter has the authority to tell you to leave! Just because something is in writing doesn't mean its official.
I hope this has been resolved a long time ago. If not, good luck.
Answered Dec 31, 2010
Edited Dec 31, 2010