If it's only the retainer clip that broke, and everything else is fine, and you can't find a suitable way to repair it, you could try hot glue.
Insert the memory properly. Make sure it's seated right, and working. Then take some hot glue and form a glob that gets under the edge and comes around and up onto the top of the ram card.
Not elegant. But it might work fine. And being a surface contact, shouldn't harm anything.
I've used hot glue inside electronics at times when there wasn't any other option. And it works fine. And it can be peeled up manually if it was later necessary to replace the memory module.
My preferred option would be 2-part epoxy. It can withstand a ton of heat. And its permanent. Of course permanent can be a problem if something needs replacing.
Epoxy is also safe on the surface of electronics.
Naturally I have to say do it at your own risk. But I've never seen a problem.