Sony Z3 Xperia - Water DAMAGED!

I am very dissapointed and frustrated at the fact that I renewed my contract with Vodacom to the Sony Z3 Xperia. After having this phone for 1 week i decided to test it by taking a pic under water. the phone was for no longer than 5 seconds under water and when it came out it did not go back on again. i then took it back to my service provider who then sent me to Sony in Midrand who then sent me back to my service provider. For a man who travels alot for work purposes this was very exhausting for me. when i took it back to Vodacom they kept it and sent it to the technician, within 2 weeks I got a text saying we should collect it. i then went to Vodacom in Cresta and they said that there is nothing they can do and the phone is water damaged. I was so upset and demanded to speak to the Manager with no luck. All they could tell me was to call the head office on Monday. I have not called the head office as I do not have time for that. i am as operation manager and work on sites and not in an office. I feel that this issue needs to be resolved with Vodacom as they are my service provider. I really do not know what else to do. Can somebody please respond to this!