Preventing access to account - bizarre!

In dire need of someone who can help us. I’ve been trying to help my dad as he doesn’t know who to turn to anymore. He opened a trust account at FNB for an account where he is the trustee. I believe this was in 2000. Since 2016, when he was advised about a FICA process, he’s been trying to get access to the account. He goes to a branch, someone “helps” him, it’s back and forth for a while and then it goes quiet. This last time has had no progress since July. He emails the consultant and they say they’ll hopefully have an answer soon. There must be something that someone can do!!! If they look up the account, his documents including his ID are there on the system, but he has been delinked from the account. The consultant that “helped” in 2016 delinked him from the account and they don’t know why. In July this year, they created a new profile for him to link him to the account, but he has still not been linked. Surely there must be someone who can help us please?