defective keyboard, or use part of my product ONLY

I can not say I'm satisfied with this product, on the contrary, I can use it fully
Indeed, the keyboard (which was the motivation and the goal of my purchase ...) has never worked on receipt
the problem thereof is that there is absolutely resistance even with change several times power cord
He proposed that his exchange I could not accept, for the simple reason that the product was imported from China and that its delivery was too long (several weeks)
In against part, I was promised a refund only keyboard I'm still waiting ...
I sui deeply disappointed with my choice but I really wanted to this product that matched my need