Account 'pended', no notification, no explanation, no resolution

Disgusted, not at Nedbank's service agents/branch staff, but at the complete opacity of their process. Account is suddenly deactivated; no one can offer a reason. Wasted my time with the branch and help desk, who both 'sent an email to the ***** department' but can't explain why the account is frozen or when it will be lifted. I'm taking a wild guess it's under investigation because I have power of attorney to manage my mother's account - she has severe dementia and is now in a frail care home, using funds from the sale of her house which I put in savings but periodically draw down from. Fair enough that they may need to check for *****, but no notification has ever been received that the account was to be 'pended', let alone has enquired with me. this is the 2nd time it's happened in 2 years; last time the hold was lifted without apology. It's been a week since I discovered this and first enquired. Not a whisper of feedback. Meanwhile the debit orders (eg for insurance and the frail care home!) are bouncing and monthly costs are racking up...