Bad experiance with technogadgets

Good day, I want to complain about the service I received from Technogadgets, I ordered (JJRC H48 MINI 2.4G 4CH 6 Axis 3D Flips RC Drone Quadcopter RTF) for my son on the 25th of November 2019 and received it on the 9th of December upon assembling the drone I found out that it was faulty and reported this the next day, I sent pictures and a video to show that the unit is faulty. I was told I will be refunded I must send my banking details and I did that but till today I'm still waiting for my money .