Used product sold to me

I'm trying to return a defective product that you sent me but I find myself going back and forth with you about this. First of all you sold me a used product which is completely unacceptable and now I can't return it. I scheduled a return with you to a business address but you want to collect on a Saturday which makes absolutely no sense because I will obviously not be there! Your call center says I can't change the address but I should re-log the return which was cancelled on your side so I can do this but I log the return because your site won't let me. It's really annoying that I'm constantly having issues with the products you sell which seem to get worse with each order. I want to return the USED product you sold me and have it exchanged for another. No one should have to go through such trouble when the fault lies with you, the seller.