When a buy shows as Pending or Transaction Processing, it simply means the purchase is being completed and confirmed on the blockchain. This is completely normal, and nothing is lost while it is in progress.
The best thing to do is give it a little time to confirm on the network. If the buy cannot be completed for any reason, your Naira is automatically refunded to your balance, so you are never left out of pocket (see "My buy failed").
If a buy stays pending for a long time, reply with your Celia Cash username, the coin and amount, and, if you have it, the transaction hash, and we will check it on-chain for you.