No response on return and refund request

I ordered 2 x security cameras that were delivered on 26/04/2021. On 27/04/2021 we found that they did not connect to the wifi and immediately requested a return and refund as per the T&Cs. I received no response. A 2nd request was logged on 29/04/2021 and I added their admin email address to the mail trail. No response received. I have also logged a ticket via the website and still no response received. There is no other method to contact them and I want a refund.