I had four time the same issue with a MBP 2011, the HDD cable was failing again ad again. First time they replaced it, next time they replaced the cable plus the HDD, third time they replaced cable plus logicboard, fourth I got a new MBP 2013. All for free, without Apple Care. Every time I got my laptop back in less than 4 business days (also the replacement unit, I received it at home even before they had picked the old one).
This is true heaven if compared to my nightmarish experiences with DELL, ASUS or ACER (as a private customer, not business).
About the repeated MBP issue, I blamed my way of carrying it around (with a passport bag) and the fact that the cable was directly in close contact with the unibody shell.