Standard Bank Call Centre Harassment

Standard Bank harasses us by making up to 12 calls a day from call centers. We have often reported it to them and requested that no 011... / 012... calls be made to us. All correspondence must be through our local branch or by email, but it never stops. After banking with Standard bank for 44 years we are now considering swopping to another bank due to their irritating calls the last 3 months.