Review TV WAVE 65" SCREEN TURN BLACK WHILE TV WAS ON

My tv screen turn black while was on.its already 2 weeks i had call rawat company.but no action has been taken till yet.and everytime the person who take the phone when i call keep telling me they dont know when the technicien will come to see th TV...PLEASE WHAT SHOULD I DO???As my kids are at home its school holidays they keeps annoying me they want to watch tv...