Bad Service form Wesbank

I called Wesbank in mid January 2016 to notify them that I have switched banks and to give them my new bank details where they will be taking my car installments from. On the 28th of January, when my installment was due , they took the money out of my old bank account. My old bank then returned the money to Wesbank. I then called Wesbank, to ask them why did they debit my old account, it turns out that they did not change my bank details, they sent me an email to confirm the new bank details. On the 2nd of Feb, the debited my old account again, my old bank returned the the money again to Wesbank. I emailed Wesbank to ask them to stop debiting the incorrect account. They sent me an email 4 days later asking my to complete a form to chnage my details! I rep**** to the email asking them why I should complete the form, my details have been changed already. I then called customer care and they could assist me. This is the definition of bad service! I have waited time and money trying to sort this out. Now Wesbank wants to create more admin for me, when I have provided them with all the information they needed to do the right thing!<br> This is unacceptable!