Open up a claim via eBay - this can be ended, once things are sorted - though you maybe only have a short-ish window of opportunity to do this.
45 days after the transaction started?? Reading your post, my Spider-sense did tingle when you said the seller requested more time. Maybe nothing, but maybe waiting for the time period to run out.
And a full refund if the item doesn't turn up. And state a time frame for this, and stick to it. So, another week or two, and then go for the full refund.