Shut down the whole operation

I received an SMS letting me know that my package would get delivered by 5pm, they sent another SMS at 20:44 to notify me that the delivery attempt failed. When I tried to call them to try and get assistance the lady I spoke to told me she doesn't know why they can't deliver my package today. I cannot get ahold of them now because the line extension is at capacity. Tried WhatsApp, but the person just stopped replying. What kind of business are they running. I don't understand how customer service people can just decide not to reply to customers, what is the point???