selling faulty good with 1 month guarantee

This shop is a joke I bought a kangertech kbox 70 from them 1 month ago. Till now it's been working y.dat it just stopped working. I phoned them and asked can I bring it in to have a look at it. And this girl flatly refused to help me. Saying they only give 1 month guarantee. When every other shop that sells the same device gives a 3 month guarantee. To top it off the to young guys selling the products did not give me any information of the device with regards to battery replacement. I will never buy anything from them ever again bunch of ************ giving 1 month guarantee when the device actually gets 3 months. I think they are selling defects to customers