TTK Prestige — Induction cook top PIC 14.0

Had raised service request( as it was showing error code E8) n panel stickering for the induction cook top on 7th of December. They provided the job number(BANG[protected]) n told with in 2 working days they will take the product for service but they didn't turned up. After continuous followup they picked it on 15th of December i.e after 8 working days. They kept the induction cook top in service center for 15 days but issue is not solved. First error code E9 was showing but once it came back from service now error code E8( according to manual they have left coil sensor open) is showing which didn't happen when gave it for service. The technician who had come to deliver the cook top is not responding for calls n ttk customer care gave service centers number there no one is picking up the call... When they delivered the cook top on 30th they charged ₹700 for fixing the cook top... I don't understand whether they fixed it or made it even worse... Pathetic service from TTK customer care and service center.