INCREDIBLY **** SERVICE AND PRODUCT

I have a Hisense E76 infinity cellphone that gives me charging problems. I had it at the customer service centre in woodmead and at first the technician told me there is nothing wrong with my phone, then Rhona told him to open the phone and check. He brought the phone back to me +- 10mins after that and told me no fault found. How did he open up the phone check it and put it back together under 10 mins. There is also now damage to where my sim card slot is that was not there.