Having some issues with a private repair guy?

ok I had a boat that i bought in back in november on 2010 the engine needed to be rebuilt so i took it to a little hole in the wall boat repair shop he said that he could rebuid it for $1300 i said ok thn so i couldnt pay him all up front so he let me do payments i did it paid it off within about 3 weeks and he still didnt finish it whcih understandable. so i give about a month and he still hasnt finished it so every week i stop in and see how he is doing and he gives me an attitude saying oh well i havent gotten to it yet this goes on for about 4 months. Finally i have someone else call him and ask and he seemed all nice to them saying oh well i need to get a special part this mind you is 4 mothns later.a week later i have thaat person call again and he says oh i have the part but its just really busy right nw cuz its spring and i usually dnt do rebuilds in the spring. So basically he keeps giving me the line about how he cant do it. Now being seven mothns in still no progress. No idea what to do about talking does not do any good. and to add to it have to proof that he is working on my boat other than the title i dont have reciets or anything. So any suggestions on what is do be done.