I have used TATA DOCOMO number from last seven years because of its service. I don"t have any problems in last seven years. If you mail company regarding any issue such balance deduction of any unwanted service activated on your number, company mail to you in much time and take action you complaint. But now a days docomo 3G service faces speed issues. Net connected and disconnected on regular interval automatically. 4G service not available with this service provider other than this no big issue with this service. Right now no signal issues on highways. But outside area signal issues till now not end.