delay in delivery of tablet after payment

Location/place: new delhi

Name of company/service: datawind (aakash tablet)

I Have submitted my on line payment on 5th of feb 2013 with the promise that they will deliver aakash tablet with in 72 hours after getting payment and now after 13 days they have not reverted from their side. neither thery are picking up the phone nor reverting by mail. my order no is PM35C8A
my contact no is 9891492150