House of Aluminium-Polokwane do not respond to request for refund on work not done

I ordered and paid for removal of old windows and fitting of aluminium windows on 6 February 2021. The aluminium windows were delivered on 18 February 2021, and on this date, they told me that their contracted builder terminated his contract with them, and that I must get my own builder to remove the old windows and install the aluminium windows they delivered.

Days after delivery I hired a builder to install the windows and that is when I discovered horrible manufacturing defects on the windows. Some window rivets were sticking out, making it impossible to open the windows, and plastic covers on all window handles were missing. I reported the defects and they only completed rectifying the defects in May 2021, after many telephone calls and emails.

I struggle to get a refund for work not done. I sent the manager, Aik Eriaye emails on 17 May 2021 requesting my refund and he did not respond. I send him reminder emails again on 27 and 28 May and he has not responded till today.