post office stole my diesel shoes

I have bought a diesel pair of shoes last year December .at new Zealand it was supposed to be delived at post office .to my surprise I sent several emails waiting for it to be delivered at my nearest post office which is Alexandra. when I went to collect my shoes on the 22 of December when I got home I found a MaQ washing powder I tried contacting them sending pictures .till today I haven't got any respond from them. they had the audacity to open the box and stole my diesel shoes .I paid for delivery from new Zealand to South Africa and R860 from them to get my shoes yho guys post office are ******* I want my money I want to be compensated I want to warn south African to stop using post office