Blatant harrasment. African Bank

I have been harassed over the last few days with phone calls from this bank from different numbers. On Tuesday alone I counted 15 calls starting at 08h00 in the morning with last one at 17H30 in the evening. I have blocked these numbers but they still phone using a different. Numbers from where the calls came from start with 087/010/011. To be exact: ***, ***, ***, *** and it goes on and on. They have even contacted my Parents in the Cape to try and get hold of me. This morning I decided to answer a call and when I asked the person why they are calling me he put the phone down in my ear. I phoned head office and explained this to them requesting that my number be removed off their base. The lady said she would get her supervisor to call me back. THAT WILL NEVER HAPPEN! What to do. Do I now expose them on social media as this is harassment?