Most frustrating online shopping experience ever

I ordered an item on 13 August 2019. The website says to allow 5-12 working days for shipping / delivery. I have not received my item. I emailed customer service and was assured I would receive my order last week. It was not delivered. I have sent three further emails, all of which have received no response. I called and it went to voicemail on 3 occasions and the message box was full each time so I could not leave a message. The receptionist answered yesterday and said someone would contact me. I have received no call back. I have yet to receive an email or call from them or any courier company that would give me any information on delivery or allow me to track my order. It is as if they took my money and don't care if I never receive what I paid for.