Mobi-trade bad service

My sister bought an iPhone 6s plus from Mobi-trade. The phone came earlier than expected and the phone was spotless. However, both front and back cameras were not working. They told her to return the phone, which she did along with the charger, cable and earphones. The courier even checked it. A few days later she received another phone without the charger and earphones. Mobi-trade told her that they did not receive the charger and earphones. She was told to sort it out with the courier. She spent a lot of money on this phone. Not cool man! Not cool.