What if my XRP and USDT have not been credited?

First of all, make sure that the transaction amount is greater than the minimum limit. 

If the amount is higher than the minimum amount, make sure that you have entered the correct cryptowallet address and, if sending XRP, that you have also entered the correct destination tag (which can be found in the "Deposit – Ripple" tab). 

Make sure that for Tether (USDT) the right protocol was used - ERC-20.

In order for us to provide information on the transaction, please send a screenshot to support@currency.com with the details of this transaction, which will reflect the cryptowallet address where the cryptocurrency was sent to, the amount and the date, and additionally write the transaction's hash/txId in the letter.