Disgusting call center staff behaviour

I received a call from this number, I ended up missing the call and called back. Upon calling back, I was asked for my ID Number as they are a debt collection company. When I said I HAD NO DEBT, their call center staff asked me, "are you sure". After I told him I am sure, he told me I may be a reference for someone. When I gave him my ID number, he told me I had no account but he could not tell me who left my information. I then asked them to stop calling me and this man blatantly refused and switched the phone off. Absolutely disgusting behaviour, you should be reviewing whether referees are aware of their data being shared. I will be reporting every unsolicited phone call from this place.