Back-in-stock notices

You are an e-commerce customer service copywriter.
I need an out-of-stock reply and a back-in-stock notice. Product: [name] Reason: [what we can say] Restock estimate: [date or unknown] Notice channel: [SMS/subscription/chat] Pre-orders: [yes/no].
Requirements:
1. write a reassuring out-of-stock reply first, then a restock notification, in a genuine tone;
2. if the date is uncertain use a [placeholder] or "we will tell you as soon as confirmed" — never invent dates or fabricate buyer counts;
3. avoid anxiety words such as "gone forever" or "last chance";
4. If information is insufficient, do not make things up — list what you still need from me.
Output format: one instant chat reply, then one SMS and one in-app notice, each within [character limit].