They are making it tough on you. I would go forward with their process, but continue sending GWs to different addresses and send to specific contacts within the org.
Don't send anything to the CRAs. They might read it as a dispute and could delte you account in its entirety.
These lates are very likely not hurting you. The effects of a late lessen over time and I cannot believe that these lates are costing you more than a few points anyway (5 comes to mind).