It took us AGES to get our own P.O Box, after being told to come back in a week, a month, 2 months! Persistence paid off in the end!
Everyone did have till 01 March to renew their P.O Boxes, I would give them another week or so & then try again?
Failing that, you can always use a friends PO Box, or most people use their employers Po Box for personal mail with no problems.