I believe this will depend on the stage of your application. If your application has already been processed to approval and the investment made, it is unlikely that you will be able to obtain a refund on the basis stated.
How can I change my application and get a part of my donation back for Grenada's CBI program?
I donated $200,000 to Grenada's National Transformation Fund and submitted citizenship applications for me and my wife. However, my wife doesn't want to change her original citizenship. I understand that for a single applicant, only a donation of $150,000 is needed. If she withdraws her application now, do we get any refund?
Obviously, the first point is that your wife doesn't have to change her citizenship rather she is gaining another one. The answer depends a lot on when the application was submitted, you would be best asking your Approved Marketing Agent to refer to the Local Agent that submitted and make a specific request. Situations like this are treated on a case by case basis but I do not know of anyone successfully withdrawing a dependant.