What is wrong with the elements on my cooker?

I have a Leisure cooker Leisure 90
Cmcf96k which was bought Oct 2011. My first element went just after the warranty expired. I had it replaced it lasted 6 months. My second one was replaced late last year and it has just gone again. Surely it must be an electrical fault or something within the cooker. Who goes through 3 elements within 2 years? Leisure are not interested.

Dicky55
March 2014