I think what is going on with the OP is the credit report and his documented proof do not agree, creating an impossible situation for a loan approval for their refinance. The new lender cannot get a DU and Seterus will not correct their records. Forget Seterus is in violation of the FCRA, filing a complaint doesn't get you refinanced.
What is your loan to value? Can you refi without PMI? Did you go with a portfolio lender for your refinance? If you need PMI (don't have 20% equity), you are fighting a tough battle. But if you do have the equity to avoid PMI, do seek out a portfolio lender, someone that will accept your proof of payment in lieu of favoring the credit report.
Mod Specialist is concerned there's an underlying reason for the late payments - a prior, old past due payment, never caught up, creating rolling lates, possibly with a lender before Seterus. How long has your mortgage been with Seterus? Check with how the dates line up.
In any event, file a complaint with CFPB. Be sure to mention the falsely reported latest have cost you irreparable financial loss, making it impossible for a refinance (even while pursuing the refi and close on a refi if you get it through). Why mention damages? CFPB has collected so much money in fines, it's being paid out to consumers. (I just received a $58 check from Citibank as part of a credit card settlement I had no knowledge of).
https://www.consumerfinance.gov/complaint/