Like Mickey, I have had two occasions where the hotel charges could not be reversed after after the report was submitted. One was here in the US and the other was outside of the country. Like you, I was disappointed....well, more like angry that I wasn't informed in advance.
My advice would be to call if you are not getting a reply to your email. I concur that you will get this payment eventually, but it's also important to let them know it's unacceptable to not meet promised deadlines.
Believe me, they would have no compunction about threatening to disqualify your report if you did not meet their deadlines. I have always been extremely vocal when something was amiss with my assignments and it (seemingly) has never impacted my ability get the best assignments.