Hi Lololoko14
welcome to the Apple (user-to-user) Community.
Re: "Money went missing on a transaction"
You can check your transactions to see what money has gone in and come out:
See your Apple Cash transactions - Apple Support
You can also check if money was transferred, by checking your card-provider statements:
Transfer money in Apple Cash to your bank account or debit card - Apple Support
if needed:
Apple Cash: See "How to cancel or dispute a payment" in Apple Support's article:
Send and receive money with Apple Cash - Apple Support
More Support if needed (info. / support / contact):
Apple Cash Support website
Apple Cash - Official Apple Support
Apple Pay Support website
Apple Pay - Official Apple Support
All the best :-)