block the outgoing call

Location/place: Kolkata

Name of company/service: Vodafone

My vodafone no. is 7890499251, last month i am port my no. Airtel to vodafone.now i have face lots of problem about vodafone service. i deactivated my Gprs pack yesterday,after deactivated Gprs Pack vodafone stop my outgoing call,i complain about these matter to company customer care they told me your credi limit is over so you pay the amount, my credit limet is 1,000/- rs, i have do not recive any call or text from vodafone about credit limit, my monthly average bill from last 1 year is rs. 450 to 500/- my usege not to much so how can over my credit limit,please do the faver as soon as possible