PEP Cellular not operating according to Consumer Protection Act Policies

I Bought 6 phones Hisense U50 for our phone system at work from PEP Cellular at the Mall at Reds on 08/11/2021. We pretested the Android app for our phone system on other Samsung/Apple/Huawei phones and requirement was Android 7.1 minimum. The Hisense U50 phones I bought has Android 8.1 and conforms to the requirements. I could not test the app instore when purchased. I called PEP Customer Care today after struggling to get the phones to work with the app since clearly there is something wrong on the Hisense Android operating system or a pre-installed app having issues. I want to return the phones of which 5 was unused since one used for testing and they refused to refund or exchange after 3 days. I will open a CPA case regarding this issue. To pay R 8000 for 6 phones and useless is a customer ripoff it has not been used.