Unsatisfactory customer service

I ordered shoes online from toughees on 17 Dec for my niece. They wear brown shoes and it’s hard to find in the shop so i found on toughees online. The sent it the next week but I got a size 6 box with size 3 shoes inside. I ordered early so that i know we have it and we had been struggling to find brown. I logged an exchange the very same day. I got an email from Yershin Archary on 22 Dec saying they’ll arrange the courier pick up for 5 Jan! I immediately express my dissappointment and he assured me they will do their best to get the shoes to me on time. He did CC Raymon zibani and Natalie Fay van Schalkyk. He assured me that they did i have the correct size. Only after i emailed Yershin again on 6 Jan did he log the exchange for 7 Jan and said they’d first inspect the shoes in the warehouse and then send me the correct pair! He said he’d keep an eye out for them. So on the 12th I still didn’t hear anything and i sent him a mail. He did not respond. Today on the 15th I mailed again. Still no response.