DON'T buy car batteries at Walmart!!!!

Walmart is running a **** with the car batteries. Once you buy a battery and as long as the warranty is on, you can only change the battery for another one the same, no refund policy. My battery died in less than a month and all they offered me was to change it for a new one, or so they say, exactly the same brand and type. So what are my chances of the battery giving me same problem in a month or two? So I basically lost my money or my time.