I recommend you to just spend that transaction. Create a new transaction using the one that is stucked and use a hight fee (enough to pay for both tx), this is called CPFP.
He can't do that because he is using Cash app, a custodial service. CPFP doesn't work in this situation because Cash App doesn't give him access to the private keys. On top of that, another centralized service (the casino Gamdom) sent the transaction, so he doesn't control the change address either. The fees for this transaction can only be increased by Gamdom, and I don't think that's something they do. Nevertheless, it's a pretty bad estimate of Gamdom to use such low fees when they sent the transaction weeks ago.
Oh, thanks for the clarification, I did not read all the posts.
Well, he said he's new on crypto. Lesson learned, NOT YOUR KEYS NOT YOUR COINS.
Maybe you already tried but, try to talk to the customer support team of that services and see if they can do a CPFP as I see that RBF is not enabled on that tx.
Ah and... don't get frustrated, we all make mistakes in the beginning and we have all been through similar things so... take it easy
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