Poor customer service with no option to leave a voicemail

Received an sms a week ago informing me that my parcel has begun it's journey to my location. They give the link to track the parcel. This morning I receive another sms to say my parcel is out for delivery today. When I tried calling the call centre to confirm where the parcel is, I am placed on hold with no indication of when my call will be answered. Eventually there is an option to leave a voice message by selecting "0" and when I pressed it an engaged tone is heard. Clearly the voicemail box is full hence a message can't be left. I understand that they are probably busy due to black friday but this is extremely bad service from an international company. Thankfully I don't use them as my preferred courier service and I certainly will never use them in future. A week for a local destination is poor