Poor online service Cape union mart group (tread and Miller )

I went in store to purchase a shoe only to find they don’t have a size I was advice to make an online purchase as the online store has my size ,and the store said they can actually do the purchase for me instore on line of which I agreed and they proceeded and took purchase 4days later the online store came back via email to inform me the color I choose has variations ,I then informed then to change color(same shoe ,price just a different color)and I check on line they dd have another colour and I dd inform which colour to send however the store process has taken another another 4 days without processing my request and I have called their call center they spoke to a lady by Fatima she promised that her supervisor will call me it’s 48hours later still haven’t called me , I went into store they also couldn’t help process my exchange I called the call centre again today still they don’t know when will they process my exchange