TBH I do not even think parts stores carry refill's anymore. Would have to special order. You would be about the first person in years I have heard actually want them. They were the cheap way out years ago. Now a cheap wiper is $4. They get frozen to windows, pulled, snapped. They loose their spring from use. They are actually meant to be replaced. I have refilled stainless wipers in some of the classic cars that I have had and it's a pain to get them right. I wish there were off the shelf replacements for those, but not always.
As far as what I buy. Either the Trico wipers from Walmart or the middle of the road RainX. ~$20 per set. Anything more is a waste, and going to Autozone is a rip. Wipers are a large markup at those stores along with washer fluid
Advance Auto stopped carrying refills a few years ago. The newer style blades made by aftermarket (Trico, RainX, Bosch, etc) are all once piece these days. Buying them at auto parts stores is a high mark up item and can be cheaper if on sale and you have a coupon or a rebate gift card.