Cannot even get banking details changed

We've been trying for 2 months to change the debit order mandate on our Supersonic account. When you call in, the line is so bad you cannot hear the person. Last month we eventually got to speak to someone who sent us a form to fill in and send back to them. (On a no-reply email address, but she assured us she would get the email and that the account details would be updated accordingly.) So yesterday the sms comes through that the debit order will go off, and guess what? Old account details. Phoned in and spoke to Ferriti (at least I think that was her name, because again, the line was so bad I could not hear her). She assured me she had manually updated the debit order details. Check this morning, and would you believe, they tried to debit the old account again! The level of sheer incompetence here is astonishing! If my internet gets cut off due to non-payment, after I have tried numerous times to give you the correct debit order details, I will see you in court! I make a living by using the internet, and you and your GROSS INCOMPETENCE will be held liable if I cannot access the internet. Every damn email address on your website to contact anybody, be it support or customer care or finance goes unanswered. You LIE to customers when they call in!

You can send an email with an apology for your incompetence, together with banking details where the payment can be made, and make sure to deduct the amount that I was charged by the bank because YOU tried to debit the WRONG account!