Rude employee

I received an email from Buffalo that my parcel has been successfully delivered a few minutes ago. I then called the people at my house to verify if this is actually true as I had not received notification that someone had entered my estate. It was then confirmed that the parcel had not been delivered. I then called Buffalo to find out where this parcel had been delivered as no one received it at my house. The agent I spoke to was extremely rude and she utterly useless. She could not let me know who signed for my parcel and where it was delivered. I have never experienced such rudeness from a call centre agent. Absolutely disgusted and disappointed.