Change in bank account details

I requested a change in bank details as I've moved over to a new bank. Telkom confirmed they only accept changes to bank accounts older than 3 months. I responded I'm happy to make manual payments until the account is 3 months old. Telkom said I would have to make manual payment 10 business days before my debit order date which would be 5 days before I earn my salary and impossible. If payment is not made before those 10 business days they would still try take the debit order from the old account and when it bounces I would be liable for their fees. From their perspective it was either pay the fees for the debit order bouncing or keep my old account open and pay a similar monthly cost. Outrageous.