Set Timeout in WCF via Reflection

I need set a timeout when i consume a WCF.

Exception: An exception of type 'System.NullReferenceException', the variable propertyInfo is null. I cant get the property timeout of proxy type.

I Have the follow code, and i have error when i set the value. (I hardcoded "1000")

private object GetWCFInstance(ref CompilerResults compilerResults, string WCFAddress, string contractName)
    {

        object proxyInstance = null;
        // Define the WSDL Get address, contract name and parameters, with this we can extract WSDL details any time
        Uri address = new Uri(WCFAddress);
        // For HttpGet endpoints use a Service WSDL address a mexMode of .HttpGet and for MEX endpoints use a MEX address and a mexMode of .MetadataExchange
        MetadataExchangeClientMode mexMode = MetadataExchangeClientMode.HttpGet;
        //string contractName = "IService1";
        // Get the metadata file from the service.
        MetadataExchangeClient metadataExchangeClient = new MetadataExchangeClient(address, mexMode);
        metadataExchangeClient.ResolveMetadataReferences = true;

        //One can also provide credentials if service needs that by the help following two lines.
        //ICredentials networkCredential = new NetworkCredential("", "", "");
        //metadataExchangeClient.HttpCredentials = networkCredential;

        //Gets the meta data information of the service.
        MetadataSet metadataSet = metadataExchangeClient.GetMetadata();

        // Import all contracts and endpoints.
        WsdlImporter wsdlImporter = new WsdlImporter(metadataSet);

        //Import all contracts.
        Collection<ContractDescription> contracts = wsdlImporter.ImportAllContracts();

        //Import all end points.
        ServiceEndpointCollection allEndpoints = wsdlImporter.ImportAllEndpoints();

        // Generate type information for each contract.
        ServiceContractGenerator serviceContractGenerator = new ServiceContractGenerator();

        //Dictinary has been defined to keep all the contract endpoints present, contract name is key of the dictionary item.
        var endpointsForContracts = new Dictionary<string, IEnumerable<ServiceEndpoint>>();

        foreach (ContractDescription contract in contracts)
        {
            serviceContractGenerator.GenerateServiceContractType(contract);
            // Keep a list of each contract's endpoints.
            endpointsForContracts[contract.Name] = allEndpoints.Where(ep => ep.Contract.Name == contract.Name).ToList();
        }

        // Generate a code file for the contracts.
        CodeGeneratorOptions codeGeneratorOptions = new CodeGeneratorOptions();
        codeGeneratorOptions.BracingStyle = "C";

        // Create Compiler instance of a specified language.
        CodeDomProvider codeDomProvider = CodeDomProvider.CreateProvider("C#");

        // Adding WCF-related assemblies references as copiler parameters, so as to do the compilation of particular service contract.
        CompilerParameters compilerParameters = new CompilerParameters(new string[] { "System.dll", "System.ServiceModel.dll", "System.Runtime.Serialization.dll" });
        compilerParameters.GenerateInMemory = true;

        //Gets the compiled assembly.
        compilerResults = codeDomProvider.CompileAssemblyFromDom(compilerParameters, serviceContractGenerator.TargetCompileUnit);

        if (compilerResults.Errors.Count <= 0)
        {
            // Find the proxy type that was generated for the specified contract (identified by a class that implements the contract and ICommunicationbject - this is contract
            //implemented by all the communication oriented objects).
            Type proxyType = compilerResults.CompiledAssembly.GetTypes().First(t => t.IsClass && t.GetInterface(contractName) != null &&
                t.GetInterface(typeof(ICommunicationObject).Name) != null);

            // Now we get the first service endpoint for the particular contract.
            ServiceEndpoint serviceEndpoint = endpointsForContracts[contractName].First();

            // Create an instance of the proxy by passing the endpoint binding and address as parameters.
            proxyInstance = compilerResults.CompiledAssembly.CreateInstance(proxyType.Name, false, System.Reflection.BindingFlags.CreateInstance, null,
                new object[] { serviceEndpoint.Binding, serviceEndpoint.Address }, System.Globalization.CultureInfo.CurrentCulture, null);

            System.Reflection.PropertyInfo propertyInfo = proxyType.GetProperty("Timeout");
            **propertyInfo.SetValue(proxyInstance, 1000, null);**
            object check = propertyInfo.GetValue(proxyInstance, null);
        }
        return proxyInstance;
    }                

Thanks