Error when calling a method on a stub !!

[Brand, Olivier]

Could someone explains me why I get this type of message when calling a method on a 
returned stub. 
The message seems clear but cannot see where is the error....

Extract of the messages for getPrice:

<message name="getPriceResponse">
                <part name="chargingServiceResult" type="result:resultType"/>
        </message>
        <message name="getPriceRequest">
                <part name="user" type="user:userType"/>
                <part name="item" type="item:itemType"/>
        </message>

Extract of the port type:

<portType name="ChargingServicePortType">
                <operation name="getPrice">
                        <input name="getPriceRequest" message="tns:getPriceRequest"/>
                        <output name="getPriceResponse" 
message="tns:getPriceResponse"/>
                        <fault name="chargingServiceException" 
message="tns:chargingServiceException"/>
                </operation>

Extract of the Java Binding:

<binding name="JavaChargingService" type="tns:ChargingServicePortType">
                <java:binding/>
                <format:typeMapping encoding="Java" style="Java">
                        <format:typeMap typeName="user:userType" 
formatType="com.vodafone.global.charging.user.UserType"/>
                        <format:typeMap typeName="item:itemType" 
formatType="com.vodafone.global.charging.item.ItemType"/>
                        <format:typeMap typeName="result:resultType" 
formatType="com.vodafone.global.charging.result.ResultType"/>
                </format:typeMapping>
                
                <operation name="getPrice">
                        <java:operation
                        methodName="getPrice"
                        parameterOrder="user item"
                        methodType="instance"
                        returnPart="chargingServiceResult" />
                        <input name="getPriceRequest"/>
                        <output name="getPriceResponse"/>
                        <fault name="chargingServiceException"/>
                </operation>

Extract of the service:

<port name="JavaChargingService" binding="tns:JavaChargingService">
                <java:address 
className="com.vodafone.global.charging.SOAPChargingServiceImpl"/>
</port>

ERROR:

org.apache.wsif.WSIFException: Method getPrice(class 
com.vodafone.global.charging.user.UserType, class 
com.vodafone.global.charging.item.ItemType) was not found in portType 
{http://global.vodafone.com/wsdls/charging}ChargingServicePortType
        at org.apache.wsif.base.WSIFClientProxy.findMatchingOperation(Unknown Source)
        at org.apache.wsif.base.WSIFClientProxy.invoke(Unknown Source)
        at $Proxy0.getPrice(Unknown Source)
        
Olivier