Has anyone dealt with NCB Management debt harassment? What did you do?

I’ve been getting nonstop calls from NCB Management about a debt they claim I owe. They’ve been calling me several times a day, sometimes even early in the morning and late in the evening. I’ve asked them to stop, but they keep calling from different numbers. It’s gotten to the point where I’m feeling stressed every time my phone rings.

I’m not even sure the debt they’re talking about is valid. They won’t send me any real proof, just vague info over the phone. I’ve read a little about debt collection laws and that this might count as harassment, but I’m not sure what steps I can realistically take to make them stop.

Has anyone else had experience with NCB Management or similar debt collectors? Did you file a complaint or take legal action? I’m open to advice or just hearing other people’s stories to know I’m not alone in this.