Public MustOverride Sub refundVolume ( _
	user As String, _
	volume As Long, _
	billingText As String, _
	referenceCode As String _
)

public abstract void refundVolume (
	string user,
	long volume,
	string billingText,
	string referenceCode
)

public:
virtual void refundVolume (
	String^ user, 
	long long volume, 
	String^ billingText, 
	String^ referenceCode
) abstract