Your rejection email will have included a reason for why they were not able to accept your submission.
Read it carefully and review the document(s) you submitted. Once you have the correct document, please upload this to either your ETN Online Wallet, or the Resolution Centre when requested by a KYC reviewer.
Perhaps what you submitted was too old or maybe it is the wrong type of document? Maybe the name/address doesn’t exactly match the information you supplied in Tier one, or you have redacted (covered) some important data that the KYC reviewer needs?