Cisco — poor service and poor quality

my cable operator suggested me to take this set top box for clear digital clarity on my LCD. inspite the quality of picture was good for a few days,the picture use to be stagnant for most of the times and it never worked smoothly.inspite of giving several complaints to my cable operator,he use to systematically ignore my complaint,as i had paid him yearly charges for the same. then he suggested me to change the wire thru which the cable is supplied.even then it didnt work out. and now the cable operator is not even responding my phone calls.