I bought my RW4 in July and only put 50 miles on it before getting the "stop riding" email. Based on the estimated time to get new tires and tubes, I requested a return of the bike.  Rad Power Bikes approved the request, even though I was well beyond the 14 day window, and started the return process.  Because of this, I ordered a RadRunner Plus (nice bike) and used that box to return the RW4.  I had to lengthen the box by 8", but it all worked out.  Fedex picked up the RW4 this morning.

It seems they are very willing to accept returns, which is the right thing to do.  If you don't have a box to return your RW4, it may take some added time as they don't have a plan yet to get a box to you.