Tata Sky — Alert signal appearing on set top box. and no display on TV screen

Alert signal appearing on set top box. and no display on TV screen. since Saturday 3rd July 2015 i have been complaining to Tata Sky Customer care related to the problem WO No. IYA2KYG, then on 4th July'15 with same WO. No., then again on 5th Julu'15 with WO. No.IYPJEQR, again on 5th July'15 evening with WO. no. IZ1KXRY, again on 6th July'15 same WO. No., then again on 7&8th July'15 with same Wo. no. Every time its being said it will be attended withing 24hrs. no one turned up. Every call charges minimum Rs.50. above that the customer support team will send a msg. saying that the Service technician will visit between certain time slot and have to wait for his arrival leaving all other necessary jobs.