In case the payment of the value of input service and the service tax paid or payable as indicated in the invoice, bill or, as the case may be, challan referred to in rule 9, is not made within three months of the date of the invoice, bill or, as the case may be, challan, the manufacturer or the service provider who has taken credit on such input service, shall pay an amount equal to the Cenvat credit availed on such input service and in case the said payment is made, the manufacturer or output service provider, as the case may be, shall be entitled to take the credit of the amount equivalent to the Cenvat credit paid earlier subject to the other provisions of these rules.
so in your case you can take input credit after payment is made to the service provider till then you are not allowed.