call is connect after trying several time and bad network

Location/place: kolkata

Name of company/service: TATA DOCOMO

i am using 123 free T-T calling pack for 5-6 month but when ever i call to a particular number maximum time company replys that, the ” number is switched off ” and as i called again and again after trying 4 to 5 times or more the call will connect .some time when the company replys against my call to that particular number that “the number is switched off” but when i call to that number from another number( after cut the call) i am astonished to see it is ringing .the call never connect at a chance never. i am fed-up to call again and again . i never inform even in emergency .and call ended automatically for network failure several time.its a horrible problem please help.