Dispute matter

My claim for my daughter's disability was rejected due to my ITRDD form being filled in incorrectly. I was told to file a dispute and have been trying to do that for months. I even called the contact centre but I have not been successful in submitting the claim.Someone called me back and tried to assist and failed, he said he was going to call me back, but never did. Can I get a direct email address where I can submit this form please?