Jonway - Bigboy S****** Faulty

HI

I got my Bigboy s****** new with no milage , after 4000 Km i started to get problems where it feels like its loosing power , i have taken it to the branch , they tried several time, i can not fault the branch , they tried there best, now the branch have escalated it to HO Jonway

http://www.samotorcycles.co.za/?gclid=CjwKCAiAoNTUBRBUEiwAWje2ljxDdRL-dT91vh3qj229X4_OjaYRo5U4gYqHdxUouBiRH_ilVYptqxoCMnsQAvD_BwE

Now it going back and forth and the s****** dont get fixed , i am now stuck and hopefully this post might help , because mailing and calling dont help at all. I either want my s****** to work properly or a refund , easy I see now the reviews is very bad and jonway dont respond, damn , i think its a loosing battle here Next thing will be the Consumer affairs

Please who ever can help me