Sender says he sent over 500$. I got around 50$. Blockchain writes I received around 50$. Sender claims he sent 500$ and no money came back from this transaction.
So now I am stuck in nowhere

What should I do, how i should react and which actions should I take?
Let's take a step back. Can you tell me which wallet you're using, wether or not you see transaction 2508f218db9663057bc863f6d986eb84fe8a96f31c61e681847c327dcfce503a in your wallet, and which balance (in BTC) was added to your wallet after you received transaction 2508f218db9663057bc863f6d986eb84fe8a96f31c61e681847c327dcfce503a.
If you only received 0.01771605
BTC as unspent output from this transaction, the sender has either messed up or intentionally scammed you.
Do not look at blockchain.info's block explorer. It does not matter what they say happened. They are just a visualisation tool, nothing more nothing less. When they have a bug or mess up completely, it has zero impact on your wallet. Also, try to give number in BTC instead of USD. The BTC<->USD exchange rate changes all the time. When you say you received $50 in BTC, it's a completely different value today as it will be in 2 weeks.