Return good after purchase

Hi there, i have bought a bedframe from Saray Meubles and was delivered on Wednesday 12/8. Upon delivery we realise that the bedhead is too big to be transported to the first floor of our home. We tried many solutions with them but failed. We have requested for a product return and they have refused it by saying that we have open the plastic of 1 box and they do not have return policy. Would you be able to help us. We are stuck. Thanks in advance for your help. Looking forward to hearing from you.