Damaged curtains

We bought curtains from @Home about 8 months ago. The curtains has block out lining. We washed the one curtain for the first time in the washing machine, according to the label, my wife used a gentle wash. After removing it from the washing machine the lining came of in flakes. The next day i took the curtain back to @Home, the sales lady said she will exchange the curtain for the same kind, but there where none left and i should return the Monday to see the manager about exchanging it for a different curtain. The other curtain was hand washed and just soaking it and not rubbing it or spinning it , it was hung up wet. The same thing happened to the other curtain as well. On the Monday i took both curtains back and spoke to the Manager of the store who told me i can not machine wash it ( not what the label said) i informed him that the other one was hand washed and did the same. He said he wants the sales slip which i did not have after 8 months, i asked him to look on the system but he said the system only keeps data for 3 months and can not help me. I think the service from the manager is poor and so the material.