I have also heard nothing from the USA customs and are still listed as being in the country.
It has been 4 weeks since I have overstayed my visit and I would have thought that P&O would have resolved it by now.
I will give it another 2 weeks and if I am still supposed to be in the USA I will email P&O again, however when I was reading todays Sunday newspaper I read an article on the Holiday Q&A page and found that someone else had written about this cruise and they also had an email regarding still being in the USA.
This is the advice the Holiday Guru states: