I regret taking this contract with mrprice mobile

It's hardly a month with Mr price mobile but I really regret taking this contract. I changed my banking details but the consultant never advised or gave me proper information that they won't be able to debit because the debit order has been loaded I should rather make an EFT she said it will be debited on the 27th as my pay date was on Saturday but till today nothing has been debited. I have been calling and sending emails only today i am told they did not debit because i changed the details late i have never seen such incompetence like thus in my life. 1st time with this company and my life is hell when did I not go with the companies I am used to and I explained that that account is closed they won't get money now this is going to affect my credit record I am beyond p***d right now and they send emails but there are details to transfer the money