Bad customer service

I had the worst experience with this courier company. I had a package that needed to be delivered with tracking number: BUFZA***YQ. I received a notification that my parcel was delivered but I did not receive it. I went to the online tracking on their website and it shows that someone else signed for my package. I contacted the via email, whatsapp and all other mean I could and NO ONE came back to me. I even gave them detail that we have 24 hour surveillance cameras and I can prove that no one was at my house to deliver this package. On the online chat someone answered me to say it was delivered, but when I mentioned that it was not delivered to me and that I have proof that it was not delivered, I was Ignored. This is the worst client service I have ever had. We work with couriers everyday and this company is just the absolute worst. Very unprofessional!