Warranty Terms Not Specified

I have had my Sony Xperia Z2 for 20 months and now the screen is not responding. My phone is still in excellent condition with the original packaging stickers on. I went into the Telkom store at Gateway to get my phone looked at and if necessary, sent for repair. I was told that my phone only had a 12 month warranty. I disputed this saying that no one had ever informed me of a 12 month warranty. I asked for a copy of my signed contract and he informed me that he would have to email to get a copy through. I did get the copy sent to me and not even in the terms and conditions is it stipulated what the warranty period is! I was most definitely NOT informed of the pathetic 12 month warranty offered and more so had I been informed, would not have bothered going into the store today! I have had nothing but endless grief with Telkom Mobile, I have had to deal with limited to no signal more often than not and now that I have the first problem with my well looked over phone, I get told \sorry, but the warranty has expired\". I called the telkom mobile helpdesk, only to be told that the store are the only ones who can help me!!!"