Having dealt with Apple on a number of issues, I can state without fear of contradiction that it is a wonderful company to deal with. If their people even suspect that the problem is Apple's fault, then they do what they can as quickly as they can to make the buyer whole. I am aware of a problem with the MagSafe "T" connector. My 2009 MacBook Pro shipped with this type of connector. Here it is more than three years later and I have not a hint of fraying. My MagSafe connector shows not a hint of fraying.
From everything that you say, it sounds like the "technicality" that resulted in your being denied a free replacement is that Apple determined that you are deliberately abusive to your equipment. And, I'm being kind.