Having to change password nearly every month

Having to enter a new password almost every month as " apparently im entering the wrong password even though I write them down and also use my finger print to access my account. Best part is when creating a "new password " and use the previous one ,i get prompted that I cant use the the same password - ironic when i cant log on using the password because it "incorrect". And now i cant do any transfer as I now once again been locked out my app as I now need to give authority to FNB to take a phone of me.. Absolutions bull !!