Missed returned application becaue of address change

Hi All,

I sponsored my wife for inland spousal PR Sponsorship program using paper application. My wife's application got returned due to a missing document, unfortunately we had changed the address and hence we couldn't receive the returned application as the address was not updated by the time they returned our application. We came to know about the return application as we posted a query using the web form. Now we don't know the reason of the return or the missing document in our application because we never received them and it says that the package is returned by Canada post to IRCC. What happens in such cases, is there a way I can contact them and ask them to redeliver the application to a new address. Or do I have to apply with a fresh new application. I tried calling ircc but they are not answering call due to reduced staff because of covid. Please help immediately. Thank you in advance