It is really hard to offer any useful advice with so little information.
Can you add more detail?
Did the buyer open a case through Ebay or was this a payment dispute where their bank/Paypal made a judgement.
What do you mean by the buyer's address was wrong?
Why did you need to change the tracking?
To win any case, or an appeal, you would need to prove delivery to the address used by the buyer at checkout - the address shown in 'order details' when you are logged into Ebay.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)