Paying for a device I can't use

<p>I took a Sony Xperia M4 Aqua with Telkom Mobile on a SmartPlan 50 contract for two years. I took it in for repair for the second time within that period. A few days after taking it in for repair the second time, I was told that my phone is "Beyond Economical Repair" and I have to pay the assessment fee of R188. The phone had no physical damage. I do not understand why wasn't I told from the start that my phone is unrepairable. I could have used that R180 to book it in for a repair at another place. I regret taking a cellphone contract with Telkom because at the moment I am paying for a useless device. Why do they sell products that are unrepairable? </p>