Firstly, you will need to ask the sender to confirm that the transfer details match the details of your payzy account, as there must be a full match between the details shown in the transfer confirmation and those registered in your payzy account.
You can also contact the sender to let you know if the transaction has failed and the money has been refunded. Keep in mind that sometimes, the amount of failed transfers, while arriving in the bank's system, is not credited directly to the sender's bank account.
If you need more help, you can make a support request via the yzy bot, in the ‘Help & Support’ section.