How can I stop my electrolux gas hob automatic ignition stop! EGG789BK?

i have an elextrolux gas hob with 5 rings and knobs which when pressed down intiates the ignition. The relay on the ignition seems to be stuck and so when the hob is to be lit - all of the ignitions fire up and will not turn off unless i turn off from the mains. The hob continues to work however i am unable to use my main electric oven as the two work from the same mains switch - the oven is neff. there is nothing wrong with this just not able to use becuase i need to power it from the mains. i have to turn off the mains in order to stop the ignition from continually firing - does that make sense - what can i do