Dimplex electric heater ss5858n thermostat cycling...

Question

when we first turn on the heater it runs for about 10 minutes then shuts off blows cool air and sometimes comes back on or we have to shut it off with the switches and wait about 10 minutes and turn the switches back on. the thermostat sometimes clicks when we turn it hoping the heater will come on and sometimes it does not. we called dimplex they said it was not the thermostat? it was a big ticket item (fan or heating element i don't remember) they said it would cheaper to buy another one.