Delivery address/residential address=No device

I ordered a phone last week and it was delivered to my old work address after I clearly explained to the agent that I had changed jobs and am now working at a different location. The call centre says they cannot change the delivery address unless i give them proof of residence of the company i work for? how am I supposed to obtain that? I have proof of address for where I live , i merely need them to deliver where i work and i will present my proof of address. A whole week later my device was sent back. Highly dissapointed