WORST EXPERIENCE EVER!!!!!!!!!

This is the worst experience I've ever had. I have an account with Vodacom but received a really terrible phone. After my first month I couldn't anymore and phoned Vodacom to complain about the phone and let them know I'm not happy with it. I have since been phoning every month and was informed I could apply after 3 months for another device. As with all my accounts I pay diligently and always pay a little extra. Today I called again and tried to apply for another device, not much more than I'm currently paying. I was told I cannot apply for another device at this stage. I am furious because the issues I'm having with this device is terrible. The phone lags, freezes, just switches off, gets hot, the screen is unresponsive most of the time, this phone is unusable. I cannot hear when someone phone's me, or vice versa. I have factory reset this phone 3 times times this week already. And all I get told is I must continue to use this phone until such time that I can apply for another phone. I can't believe Vodacom is willing to lose a good customer just because they refuse to give me another device for a little more than this useless one is costing me. Thank you Vodacom, this is what I get for paying my account diligently every month. You sure know how to make someone feel important. I'll never forget this and tell everyone I know what you've done and how you conduct your business and treat your customers.