channel 1 and 4 are linked

Just got my jumpertx t8sg in the post yesterday but my yaw input is on the same channel as my roll input. when my roll is on 100% my yaw reads -100%. Also when i hold down ent and power i get the logo for a brief second but it doesn't power on. I've tried the usb mode and my pc picks it up as a mass storage device and asks me to format it??

Have I just got a dud? Should I just send it back?