Spamming me with unsolicited calls

********** 540. This call center is spamming mew with unsolicited calls constantly. After repeated requests to stop phoning me they still do and they just wont take no for an answer. The call center staff that calls you never gives you a change to respond NO after answering. as such I now just don't answer anymore or when I do I just put the phone down so they speak to themselves. I am getting fed up with receiving up to 9 calls a day. It has to stop. As I run my business with my cell phone I don't have time to waste on these type of unsolicited calls. I requested to speak to a supervisor the last time and they just refused. Something needs to be done and soon. Old Mutual will never see me as a client because of this