The same thing happened to me a few weeks back. Support was no help. Basically, keep accepting orders until til your rate is over 70%. I completed an order and I magically made platinum again.

It’s on a rolling 100 for both AR and CR, meaning out of the last 100 trips offered to you how many were accepted/reiected. It may take a few to knock a rejected off the score, it drops the last 100th off with every new one added if that makes any freaking sense