Unaware of can't return sales item and refused to take something else

I bought an sale items of 5000 and I was not aware if you can't return sales items only to find out yesterday. Buy now the funny part is that I can't even get hold of the manager and I tried to call her and I sent her an email still no response. I do not have a problem if no return policy but now I don't want anything on sale and I want to take something for that amount I paid for still they are refusing... Now I need help with this matter and they are bad at customer service I even called their head office Reviva Technology at Epping I have been put on hold till the phone drops.