Webservice C # to search several files and compress them

Good morning!

Sorry for the inconvenience, I tried to make a webservice that has an invoice name, go to a folder and take a pdf file and another xml compress and return the zip as an answer but I have not succeeded, try to do I will look for it in the following way and even then I could not, seriously apologize for the inconvenience.

Greetings.

namespace BuscadorFacturas
{
    // NOTE: You can use the "Rename" command on the "Refactor" menu to change the class name "Service1" in both code and config file together.
    public class Service1 : IService1
    {
        public Buscador getArchivos(string nomFactura)
        {
            //instanciando el objeto
            Buscador seeker = new Buscador();

            //Obteniendo los archivos del directorio especificado
            string startFolder = "C:/Users/Axiliar_Sistemas/Desktop/facturas";

            //tomando captura de los archivos
            DirectoryInfo dir = new DirectoryInfo(startFolder);
            IEnumerable<FileInfo> fileList = dir.GetFiles("*.*", SearchOption.AllDirectories);
            IEnumerable<FileInfo> fileQuery =
                from file in fileList
                where (file.Name).EndsWith(nomFactura)
                orderby file.Name
                select file;

            foreach (FileInfo fi in fileQuery)
            {
                Console.WriteLine(fi.FullName);
            }

            return seeker;
        }
    }
}