Incomplete dwelling

We Contacted this Jahn Elk to build us a Wendy house , 10 by 6 Wendy house on our property in East London ,so far I have paid him R181000.00 . This Job is incomplete and have now been waiting 6 weeks for more wood from the supplier according to him. The Worksmanship is not up to standard, I need someone to come and see what i'm talking about. Unfortunately there has been no paperwork issued to me, and have not been given an invoice for anything, all i have is his name ZJ Mashava and his bank account number and the proof of payments to him. The front side of this dwelling still has to be moved one meter, and another 21 various issues. Can you kindly assist me or tell me the way forward, i am a pensioner. Thanking you in advance. Zane De la Harpe