You have definitely not given up, so what's the plan of action?
When I called their office last Friday, luckily that same guy picked up. (Maybe he is also a part time call centre guy?)
I asked him about the packet and gave him the customs retention number. He immediately remembered me.
He said since I stormed out of the office, they felt that I no longer wanted the item. I sternly told him that they are liable to release the goods since I had provided them with receipt and bank statement. To which at first he said, I have to pay the said amount when postman arrives at my home with the packet. Then he said that he needs to apply for exemption but quickly changed the sentence to "We will see what we can do"
I still don't know what is to be done here. He refused to tell me his name. The tracking says the item is still at their retention center.