Bought empty ink cartridges, now Loot don't want to do a REFUND.

I have bought ink cartridges from them on 15/07/2019, the parcel reach me on 23/07/2019, were the ink cartridges were empty. I took it to the local computer shop, my printer with cartridges, the technician confirmed that my printer is fine, but the cartridges is empty. So i sent i back to loot, with a letter confirming that the cartridges is empty on 26/07/2019. Now they don't want to refund me, and keep on telling me the cartridges is ok, they have tested it... I am really unhappy about this service, i am sitting now for 4 months with this query still hanging. I have spoken to HP and they have advised that Loot refund me... Still no refund for the cartridges, and they want to send me the cartridges back... I don't trust anything coming from Loot, if they don't want to refund you for something that is not in working condition. Don't support them, and don't buy anything from them. I won't ever buy anything from them with this type of service!!!! Please REFUND me and keep your cartridges which you are saying is ok.... I don't trust anything from Loot.co.za