Return of goods - a non starter

A delivery arrived for my boss which I signed for, thinking it was his upgrade, but it was not upon opening. It was for a mobile data device. This was not ordered nor needed and yet you cannot reach anyone at Vodacom, emails come back as automated, nobody wants to speak to me even though my boss has given me authority to do so verbally and in writing. How do I get this device back to Vodacom and have it cancelled before they start charging my boss. It is so frustrating and to me, Vodacom are the leading cell network in the country. I am so frustrated to say the least. Every other company in S.A. accept a letter of authority except Vodacom and MTN. Its pathetic. If anything, they can contact me on my number to let me know how to sort this mess out. I don't want it bothering him on cell number given below.