Outstanding Balance

I bought building materials at Kwik build, they didn't deliver my good,when i went back to enquire about it, the shop has now changed, the name is Build It, i explained my problems to them, they told me they bought the shop from the previous owner the shop is now called build it, they promised to pay back my money ever since from 2014, even today i have not received the money, i used to go there every week to enquire about my money , I'm tired now cuz it cost me money for petrol to go there every week, i still have the invoice from the previous shop wich kwik built. Please help