item not received - how can I keep a case opened?

[escafandro]

Situation: Item that was not received. The item was sent 45 days ago (from China). Opened a case with eBay Resolution Center. Seller asked to resend the item. It will take another 30 days, at least to get the replacement (if everything goes fine).

Questions: For how long can I leave the case open with the Resolution Center? If I accept the offer to have a replacement send to me, may I keep the case open until I get it? Will I be still covered for a Money Back Garantee after that much time?

Thanks for all help!