Why was my “CXL - SB050RUS-Shipboard credit 50 US” cancelled?

[WannaCruise365]

I am cruising back to back booked as two 7 days cruises. The first one I have the $50 pp OBC the second cruise it was on my paperwork months ago then I just received a invoice that  said

CLX SB050RUS Shipboard credit 50 US cancelled? Can any one explain this? Thank you!

 

[Stockjock]

Usually, this has to do with switching from one promotion to a different promotion.  Not sure if that's the case in your situation.  You could call, but I am fearful of calling MSC because so many of my reservations have gotten fouled up once customer service puts their hands on the booking.