Terrible customer service!

Terrible customer service. My parcel has been stuck at customs after clearance for 4 days. Upon calling customer service and telling them I urgently need my parcel and I fail to understand why it is not being delivered they advised they will escalate and I will receive a response within 48 hours. I asked to speak to a manager and they advised it is not possible, Also showing no empathy towards the fact that I need what is in my parcel for a wedding. Terrible and shocking service.