For starters, the RMA process wasn’t clarified to me. I specifically enquired about it but as I said the only reply that came did not mention it at all.
I also asked if the original packaging (which I would have to look for needed to be included) - this was unanswered too.
Their website has a RMA form which you submit online. I did that, obtained the RMA number from there, annotated it on the package and had my friend send it when she got to the US.
Simultaneously, I also sent a message to Cardas detailing the RMA number with explicit instructions - those exact instructions also in the package itself.
This is as much as I can do to be explicitly clear when no reply has been forthcoming from Cardas themselves.
I followed up earlier today with an email detailing the sender of the package, the RMA number again and the ETA of the package from UPS which is tomorrow. I also urged them to contact me as soon as possible to facilitate payment so that work can be done on the cable as soon as possible given the deadline.
I don’t know how much clearer things can be made.
I am in a different time zone so calling isn't really feasible but I will try if I still do not receive a reply from them.