Unsolicited calls multiple times a day even though I am not a client

African Bank has been calling my phone number numerous times a day. I had to call the number back and I was mortified to find out that it’s actually a BANK 😳 Why are they calling me four to five times a day when I do not even have an account with them. I requested them to remove my number from their database, but they keep calling me. This feels like harassment now, I am exasperated and I cannot breathe or live my life. My phone keeps blowing up from African Bank!! Please help me.