When items arrived not as described...

[NierAutomata 23]

Bought a ps2 game last month from ebay, seller listed it as "good" but then when I boot it, it refuses to load in some parts and music has problems playing too. 

Not the first time this has happened to me, but what I really wanted to ask is what do you guys normally do in such cases?
In my case I'm pretty sure I can salvage the disc, looks to have some sort of spots (not rot) in the disc lower layer, and it can be removed with a disc scratch remover, but should I just wait till it's working and then give a bad feedback to the seller?
The seller doesn't reply to me, and by the look of the game it's totally him not caring and trying to flip money over. Send him some messages about the game and video of the game not working. Nothing. 
Would you guys ask for refund or just a negative feedback if you get the game to work? 

[Richardhead 2,234]

If the person isn’t responding to messages, give negative feedback. 

[DoctorEncore 3,600]

It really depends on how the item was described in the listing. If he simply said good condition, that doesn't necessarily imply the game works perfectly and may only be a description of physical condition. Or he may simply not know it doesn't run well. Disc based games can vary a bit in how will they function on different machines. That being said, he should respond to messages.

No response to messages and misleading or inaccurate description may warrant a refund and/or negative feedback. Also, depending on the value of an item, it may not be worth your time to return it so you probably shouldn't give negative feedback if you choose not to return it.

These situations can be tough.