Mtn
S4 warranty assessment

I purchase my S4 gallaxy at the store on July 2013 on contract and 4 month later I experience problems with my battery. The battery is swollen and doesn't hold charge so my screen was also affected (out of shape n bumpy) due to the extreme heat caused by the battery when charging. I visited the Mtn store in Cresta and I was advised to bring the phone in with its original box, on my arrival they told me I need to bring my headphones and everything that was in the box. Chansa M the salesman advised me to claim from my insurance straight away because warranty will reject my phone since the silver trim is peeling. I don't understand why I should claim from my insurance since this battery was a factory fault, why must I hand in the headphones if the phone is going for warranty assessment