Poor Service (NO SERVICE)

Im trying to get hold of someone that can assist me with my Billing of my account but for some reason they don't answer my calls nor can assist me. I want to pay my account per EFT but I need my account details and their banking details so that I can pay and keep my Internet going.. But ive been trying for the past week and no one can assist me, my contact details on my account has changed so I cant log in to my account and no one can assist me to change the info and help me get in to my account so I can download my statements..