Bad service from old mutual

i had the worst experience of customer non-service at the Lady Grey st branch of old mutual in Paarl.i am trying to get my investment money from old mutual with no avail.i made the application on 04-11-2019 and they said 15 work days but upto now i have received nothing.when i made an inquiry they tell me i must write a letter and give a reason why i want the money.i mean common a reason for my own money,thats ridiculous,whereas the investment said the money is instantly available without mentioning of any letter.