Reverse charge accounting

Heyy all,

ABC co ltd. who trades in Goods received Works Contract Service worth 498000

so the co. accounts this transaction as follows:

Expense A/c.........................528776

    To Creditor A/c.......................................498000

    To Service tax (Reverse Charge)A/c..........30776

Is the above JE right?

Why cant the company debit a "Service Tax Recoverable A/c" of 30776 and then after paying the Reverse charge liability, claim the ST Recoverable as refund?

Please reply

Thanks in advance ;)