When sending a payment from your BitPay wallet, you may notice that more than the amount that you sent was subtracted from your balance.
The 'change' in your transaction will be returned to your wallet, but it will be sent to a new bitcoin address associated with your wallet.
If you do not see the funds in your wallet yet, then your transaction may not be confirmed on the bitcoin network. You can check the status on any blockchain explorer, such as BitPay's Insight (insight.bitpay.com).
The funds will appear back in your wallet (and be spendable) once the transaction has been confirmed.
For more information, please see the following Bitcoin Wiki article regarding how change addresses work: https://en.bitcoin.it/wiki/Change