For whatever it may be worth, the couple of times I have had issues with items purchased at RockAuto (over probably 100 orders in 11 years), the automated warranty/return portal has served me well enough. Automatically generated shipping labels and full refunds with the option to pay in full to receive a new item before sending the old (with a full refund upon receival of the defective product) have kept me in commission quickly enough that I have no issues taking on the risk of buying from them.
A phone number to call would be nice if needed, but it is a non-issue for me. That is, after all, why they are cheaper to begin with. In other words, when I have had issues, they have taken care of them, despite not talking to me on the phone about it.