FNB Business Call Centre, new account.

I recently opened a new business account with FNB, I requested a mandate to the account for my business partner. More than 1 week later, this morning at 7:30 they called me, I declined the call due to a early meeting with a client. The reason for this complain is their professionalism and business etiquette that ****ed me of, everytime I declined the call, the called back x 9 in a row immediately. I eventually blocked them on true caller so they can stop calling. Can't the person realize calling I am busy, reason for declining the call and call back later. I mean 9 x rejections and you keep trying. Is this how FNB handle new business clients? What business etiquette is this.