Debit Order Error

I have had the worst experience with supersonic when it comes to billing. They billed me 2x on my invoice and before the debit order was run I had a confirmation from their social media team that they will correct the error on their side and correct the invoice to my dismay they did not do that. It’s been a week of following up with them for the refund and all I get is “ our billing department..... sorry for the inconvenience “ . I’ve had a debit order bounce because of this.