Admyntec failed to update my banking details despite early notice

I have been receiving extremely poor service from Admyntec. I recently changed my bank account and informed them well in advance that my debit order details for my cellphone insurance needed to be updated so that the debit could go off from the correct account at the end of last month.

They sent me a form to complete, which I filled out and returned on the same day sometime last month. I also followed up several times to ensure everything was processed. Despite this, they still proceeded to debit my old account.

Since then, I have been calling and sending follow up emails, but I keep getting the same response that they will get back to me and assist. Unfortunately, no one ever follows through.

This has been extremely frustrating and inconvenient. I am also concerned that this situation may negatively affect my credit score, even though I did everything required on my side and communicated the changes well in advance. I expected much better service.