As Jim already asked - How are you submitting your request? They handle them immediately on receipt and I have had credits applied in as little as an hour or had it take 3 days - never longer.
Apply via email.
Put RCCL shareholder OBC in the title line. Include your name, address, booking number, ship and cruise date in the body of the email.
Take a photo of a broker statement showing you hold 100+ RCCL shares. Attach it to your email. Make sure the name matches.
Nothing else.
The shoreside concierge does not handle these. They only pass them on and it confuses things even more.
Hope this helps.
PS I received a credit for a cruise one YEAR in the future.