TRA keep shifting the goal post on claims

I have been trying to get a claim sorted with them for over a month now. Everytime it takes a few days to get a reply, and then they need more information. Now after a month they ask for information that was sent right from the start. When I try to phone them, you are on hold for 10min + and no one available to take your call to discuss the problem. I have been with them for 4 years, this is my second attempt at a claim without success. I am not happy!