Bad service, and putting blame on me for their iN

We bought a lazy boy on laybye, unfortunately I made an error of not making sure they were writing the correct details actually colour on the contract as I had to attend to my crying baby. Now we've fully paid the couch when hubby went to collect its white instead of cream. We spoke so nicely with the lady and even showed a picture of what we were looking for. Now they are refusing to give us our money back. We didn't take the couch because it was not the colour we are looking for. Now they shifting the blame on us, we should have read what was written and notified them. Fine we didn't coz we never noticed the white until yesterday, the couch is still with them at their warehouse and they still don't want to pay us back