Yeelight Smart LED Lamp D2 will not power on


I have a Yeelight Smart LED Lamp D2. No matter what I try it will not power on. I’ve tried to reset the thing by following these instructions but it does not respond.

TBH the thing has never worked satisfactorily, sometimes it would turn on, sometimes it wouldn’t.

I have checked the power supply / cable and it charges my iPad and I tried different cables and power supplies as well. Nothing seems to work consistently.

Is it too late for a refund or is there something obvious I am missing?