There is no lucky things, is always depends on the wagering + your section result (Like, If you in the winning situation could be there has a chance you get less). Don't ignore the claim, because at the beginning playing on stake (I don't really claim anything) and guess what after my self digging my email and start claiming there has some notification can't claim due the expired.

For rank-up reward, you can try to re-claim the reward if you missed the claim. But, I don't think people are gonna to forget that because the support is gonna contact you in 5-10 mins after your rank is up.