Exact Matatiele Is A ****

My mother bought a Huawei Nova Y61 Green DS for R4000 on the 22nd of January, this year. She took out insurance on the phone on the same day in Store. The phone got lost, she did all the necessities and went to go claim at the same store. They took the cellphone box and told her, her claim is rejected. How is an insurance claim processed in store? Why did they take the cellphone box? My mother is only left with the receipt as proof of purchase. This is store is the worst when it comes to customer service! Taking advantage of the elderly!