Store refusing an exchange/return

Spitz in Cape Town refused to take back a pair of sneakers I'm returning due to what looks like a glue not app**** properly and coming out of the shoe sole. The store manager confirmed to be seeing it and is the one mentioned that it looked like a glue, but for over a month now they keep sending me emails saying that it is not a factory fault, however, whenever I go to the store they promise to hand it over for examination or contact their customer service with no option for me to reach out the customer service department myself. Soon as I leave the store an email follows claiming the very same thing that it is not a factory fault. There is no customer service at the store, there is no telephone number available for customers to contact customer service. Their staff now is not allowed to communicate with me anymore after I went to the store and asked them to put me through their customer service, which they didn't know of any contact number we can call.