Zando online shopping should close down they are******

I bought at Zando on April three boots long heeled shuffle boot, ankle shuffle boot and painted it square toe boot I did an Eft payment.. My orders were delivered on time but the boots didn't fit so they came to collect and for the two boots the shuffled ones I requested a voucher to change the size and the painted one I wanted the refund... They gave me the voucher for 2 boots and bought the different sizes size 8, since April they never refunded my R649 for the square toe boot... I've been sending emails with no response no one is attending my refund... I was chatting to Tarren in their app live chat she was so rude... Kindly assist