Harassment without stop!!

I took out a cell phone contract over 1 year ago and it has come to light in the early days after I got the cell nr that it was a dormant nr that was put back into circulation. The nr belonged to a Mr. John Maake who owes a lot of companies money. The other companies that called has stopped after I told them it is not his nr anymore. <br> African bank however seems to be too useless to do their work properly as I have on numerous occasions more than once per day told the call center agents at African Bank to stop phoning me as this number no longer belongs to Mr. Maake. They don't even phone during office hours and I get called before 8am and long after 5pm. After 12 months of telling numerous agents that they have the wrong number it seems they still do not understand and keep on harassing me at all hours of the day with calls. I got a call this morning at about 07h30 and lost it with the consultant who told me she would remove my number. I thought to leave it at that and then after 10am I got another call from African Bank while I was in a meeting!!<br> Can somebody with more than sh#t for brains please confirm to me in writing that the harassment will stop or should I take this further?