Tick the items you want to relist in your unsold list.

That should give you a list of items.

You can make bulk edits from there or just relist them.

At least that's the way it used to work.

I do mine individually these days to make sure that eBay hasn't changed things. But I only have about 20 a day going through, so it is manageable.

My sympathies. I know how frustrating it is to get no answers in a whole 1 and a half hours, especially at going-to-work time on a weekday.