Firstly, sorry to hear this. Secondly, have you been able to speak with Cunard directly? I ask because the transcript you provided mentions they wish to speak with you regarding this, I am hoping that if you have - or are willing to - speak with Cunard directly they might understand the situation this has put you in. Not least of all the stress caused after checking in to your assigned cabin.
I truly hope you reach a resolution that is satisfactory for you both, and you can enjoy your honeymoon together.