No acknowledgement of assignment submission

I submitted an assignment for marking on the 17.03.2016. I never received any notification that it was received. I have tried numerous times to contact the call center to find out if it was received. Each time I call, I wait on the line for up to 5 to 10 minutes. When I FINALLY get through to someone I get cut off. I tried the online chat - NO RESPONSE. I tried emailing them on the 30.03.2016 - NO RESPONSE. This is ridiculous!!!