After reading the Dennis Kirk Policy more it , sounds like you need to have everything there to send back. If you threw away the box then thats you fault.
If you have everything that came with the device you can send it back.
You may return any unused and unaltered item(s) within 90 days for an exchange or a refund. Authorization is not needed, however, a call to our Customer Service Department 800-969-7501 or Technical Support Department may help you avoid an unnecessary return. Technical Support can be reached at the following phone numbers:
Snowmobile: 320-358-3409
Harley: 320-358-1914
Metric: 320-358-1915
Off Road: 320-358-3831
Please do not return goods to us C.O.D. Instead, you may use our quick and easy return process. Simply complete your Merchandise Return Form and enclose it with the items you wish to return in a secure package, apply the Authorized Return Label (ARS Label) to the package and take the package to any UPS Store®, Customer Center, Shipping Outlet, Drop Box or give it to any UPS driver. Keep the tracking number strip located on the lower portion of the ARS/Return Label for reference when tracking your package.