Sony India — new problem after repairing the previous one

Address:

Thane, Maharashtra, 421203

The technician brought the T.V after 10 days after repairing it and charged us 31 thousand but after the repair an evident black spot is visible on the screen and the technician is not ready to own it up to it. He admitted to have realised that flaw before bringing back the T.V but instead of telling us about it he brought it to our place after travelling for 2hours. And now when I am demanding an explanation, the only reaponse he has is we need to pay 8000 and wait for more 8 days.I want to state that this has caused a terrible inconvenience and I has really disappointed us as we thought high of sony's services previously. Please look into the matter ASAP.