Complain poor customer service

I made a laybye with Russell's furniture shop Thohoyandou then it expired, I went to the store in January 2023 spoke to the Store Manager she told me I can continue paying I paid then went back to the store to check if the money was reflecting that's when she told me it's canceled. I then told her to refund me that was in March I have been sending emails non stop calling no one will give feedback. They owe R2600