Tata Sky HD service problem

I have upgraded my tata sky connection to tata sky HD. There service engineer took away my old set top box and assured me that rs 300 will be credited to my tata sky account on account of this old set top box but since 24-01-2013 till today, I have not received the amount in my account. Moreover, our HD subscription is discontinued due to shortage of fund in the account on 4-11-2013. I have contacted the company’s helpline number 4 times on 2-11-2013 and was told that matter will be sorted out within 48 hours about the 300 RS And again when I contacted the costumer care on 4-11-2013 I was told that the matter will sorted out upto 6-11-2013. My HD subscription stands discontinued.