不认账
Go back on one’s word.

【发音】bù rèn zhàng

【释义】不承认所欠的账；比喻不承认做过的事或说过的话。
             Refuse to acknowledge a debt (or an account);refuse to admit what one has said or done.

【例1】敌军耍了我们一票，撤军的事不认账了。
           The enemy has pulled a fast one on us by breaking its word on troop withdrawals.

【例2】自己说的话，怎么不认账？
           How can you go back upon your word?