Hi, I recently bought a rangemaster 110 all electric, I was assured all working as it should, however once installed and the mains cooker switch is on one hob and one oven both come on without turning the knob, I have tried turning off and on again, cleaning knobs etc but cannot get the hob or oven to switch off, does anyone have any ideas on this problem please, could something have happened in transit, i have double checked with the lady i bought it from and she assures me it was all good at her house….this has me baffled and my household are sick of sandwiches and microwave meals now….help please..