public function refund($billId, $refundId, $amount='0', $currency='RUB')
    {
        return $this->requestBuilder(
            $billId.'/refunds/'.$refundId,
            self::PUT,
            [
                'amount' => [
                    'currency' => (string) $currency,
                    'value'    => $this->normalizeAmount($amount),
                ],
            ]
        );

    }
public function refund($billId, $refundId, $amount='0', $currency='RUB')
    {
        return $this->requestBuilder(
            $billId.'/refunds/'.$refundId,
            self::PUT,
            [
                'amount' => [
                    'currency' => (string) $currency,
                    'value'    => $this->normalizeAmount($amount),
                ],
            ]
        );

    }
public function refund ( $ billId , $ refundId , $ amount = '0' , $ currency = 'RUB' ) { return $ this -> requestBuilder ( $ billId . '/refunds/' . $ refundId , self :: PUT , [ 'amount' => [ 'currency' => ( string ) $ currency , 'value' => $ this -> normalizeAmount ( $ amount ) , ] , ] ) ; }
Refund paid bill.

@param string|number $billId   The bill identifier.
@param string|number $refundId The refund identifier.
@param string|number $amount   The amount.
@param string        $currency The currency.

@return array|bool Return result.

@throws BillPaymentsException Throw on API return invalid response.
Refund paid bill .