Enough is enough. Whenever it’s occurred in online business the seller was decent and gave the full 100% refund because it isn’t the buyer fault and never was in the history that the delivery company making mistakes. Even big brands do this as keeping their reputation and further businesses. Clearly you don’t care about anything else apart your profit which you get on your disrespectful way. I would say fuck your refund and spend it on medication!!!
Especially because you’re the only one who wants the cut the refund for bullshit reason. What you doing is disgraceful and cheating! You deserve to be discovered by police etc. And I’m sure even if you were out of the EBay and Amazon protection policy there is a way to report your unlawfully doing!