Frustrated

In my past review I indicated that I am being charged from April 2018 although the service was only installed in June 2018, I received a sms indicating that I will be billed pro-rata from 29 June 2018 but to date, my bill increases every month. Phoning the call centre is most frustrating, I waited >30 minutes before an agent answered, you tell her your enquiry and give her the Reference number that was sent via sms, she says that the order reference number doesn't help, all she can do is escalate the matter, how many times does this have to be escalated before something is done. She also cant tell me what my monthly account should be...can someone please help?