Impossible to get hold of Vox Telecom

I have received a letter in April to confirm my debit order instruction and that they will deliver the payment instruction to my bank. Vox has no record that they have sent me such letter and I received a further letter to say my account has been suspended. I therefore have no access to my emails . I have tried to phone them, followed their directions to the relevant department , hold on for 40 minutes + at a time and then get cut off. If I do get hold of somebody and ask them to transfer me to the particular department, I get cut off. I made an interim payment 24 hours ago but my account has not been activated yet. The problem is that I have spent a minimum of 6Hours ++ on the phone without any interruptions to try to get hold of them.