hotpoint EW74 slot in cooker

hi can anybody relate to the problems we are having with this item. The cooker was purchased new in Feb 2009 and round about April this year we noticed that the metal area around the ceramic hob was begining to bubble and the enamel finish began to lift leaving rust areas exposed. as far as I am aware all cookers are stove enamelled and should not be affected in this way. Hotpoint don’t want to know and say its down to wear and tear. we have had other cookers for 30 years without problems like this.