Do not know where my phone is

I sent my phone to Hauwei for repair of a cracked screen. First had I had no response from them. They finally arranged a courier to fetch the phone. After no response for several days phoned them and they could not locate my phone, even though it was signed for and received. Received a reference number. This went on for a few days. Finally they located my phone and there was long stories on the repair. After waiting the 21 days as stipulated by them I called again and yes, they cannot find my phone. I have called several times and received 4 reference numbers and yet no one can tell me where my phone is. Nor does anyone ever return my calls as promised. I use my phone to conduct business and having been without it for almost a month now. This is the most un-professional company I have ever delt with!!! Please do not fall for their empty promises of service and reliability. Will not recommend them