Worst Courier service ever.

Got an email from Loot to say my order has been shipped using Speed Services Couriers on the 3rd Sep 2019, and that my parcel should be ready for collection on the 4th Sep 2019. I don't know which post office this parcel has been delivered to and i can't even get through to the call center to confirm. I haven't received any communication from this dumb company. I NEED TO KNOW WHICH POST OFFICE TO COLLECT MY PARCEL.