charged for a cellphone i do not have

Why will nobody answer me, because to report a ****** cellphone that is not, seems easier that accusing a company for ********** parts. I purchased a sony experia and on purchase I dropped it and gave it back for the insurance after paying the excess. When the phone came back, the touch screen never worked and megapixels was all over. When taking it back, Edgars tried to tell me I do not know how to operate the phone properly. After going in and out, I took it to Vodacom, they immediately saw the screen is faulty, when opening the phone, it had water damage, bad workmanship and missing *****s. This phone was purchased in August last year, I have all proof that the phone was hardly used and the shady workmanship. I took my complaint to the manager, who was extremely rude and then I gave her the box, earphones etc. When I got the phone back, they still had the audacity to give me half a phone, no cover even and want to BILL me again. So now more than a year later, I pay the insurance every month, more than the phone worth, and have no phone. I have now refused to pay my Edgars account and now I am handed over. What advice do you have for me. I am desperate.