So, i had two pokemon in 2 gyms, one of them got knocked out in like 8 hours or something, all i know is i got 16 coins from that one, leaving me at 95 coins, in the other gym my sandslash defended that for exactly 2 days 8 hours and 9 mins, he comes back and i got no coins from that, i have looked around and sure i have a vague understanding of the situation with gyms and pokecoins, but no one really answers the question of why no coins are given after defending for so long, i get there is a daily limit of 50, but today (the day my sandslash returned) i never put any new pokemon in a gym, since i was at college all day, so i don’t get how i didn’t get 50 coins for the 2 long days my pokemon was defending, or at the very least 44 coins since i put both pokemon in 2 gyms in the same day (if thats how the system works), only one was knocked out way sooner than the sandslash , i’m more salty that i needed those coins to buy some poke balls since there’s an abra in front of me, ah well, if someone can help figure it out that would be great since i know im not alone on this, sorry for the long post, just trying to describe as best as i can what just happened.
Maybe you already got your 50 coins.
But wait:
After defending more than 8 hours and you got 16 Coins, leaving you at 95?
I’m out😅
Nah i never had my 50 coins thats why im confused, the other gym was defended for 7 hours and 13 mins and i got 16 coins from it so i have no clue what went on there, but yeah i already had coins from ages ago, so after getting the 16 coins i was left at 95, since i had 79 coins already
Well obviously that shouldnt happen… If you defend for 500 minutes (being 8 hours and 20 minutes) you should get 50 coins. If you didnt the only logical conclusion is that you have had your 50 coins for that day already. You should be able to check this in your journal.
If you are absolutely sure you didnt get your coins, you should contact Niantic. Maybe they can help you. Youll need alot of patience with the tech support tough…
Hmm, alright ill check the journal, if it does say i have then i have no clue how i already have had 50 coins today but yeah if i dont ill try, since i do kinda deserve the coins for a 2 day defence, cause i know i didnt do anything with gyms since i was at college, thanks though, it seems this problem really doesnt have a fix so far, at least in terms of the playerbase not knowing how this is caused 
Ah thanks for letting me know about the journal saying how many pokecoins are given, although it does seem like i didnt get 50, only 45 from one of my other pokemon, which is weird since nothing popped up about my rhydon collecting so much