Google can't answer this. Why don't you try asking them? Code is only good for the length of the rental contract and automatically ends at the end of the term. It is month to month but also is from the date contracted to that same date at the end of the term. It does not necessarily end on the first or at the end of the month. My term ran 3/13 to 4/13 and the code access ended. My guess would be your code has expired.
Gotta get a hold of the on site maint. Person
Thanks! Your answer is awaiting moderation.