Anything that arrives damaged, malfunctioning, missing parts, or not as described gets a dispute. That’s not a warranty issue. Warranty is a fall back if it fails outside of a dispute period.
If they don’t respond its a full refund, some will offer partial depending on issue but you won’t get anything if you don’t dispute.
NEVER send anything back without a prepaid return label (why pay for something they have to pay for?)

FTFY, why is it a problem if they black list your paypal? if you really want to order from them again you could use a different payment method or order from another seller.
And its not certain they will do that anyways.

buyer ’ Hey guys you sold me a broken light bulb’
seller ‘oh yea!?? here’s your money back asshole, gtfo and never come back’
buyer ‘ummm ok?’