If you have other crypto-wallets that you use, you don't need to transfer your coins to your Redeeem wallet first to be able to load up on Credits. You can actually use your own wallets to get Credits and buy gift cards!
Here's how to load credits in your account using other crypto-wallets:
From your Redeeem home page, go to the Credits page and start by typing in the amount of Credits that you would like to buy, then click Checkout directly below the amount field
Clicking the Checkout button will take you to the CoinPayments check-out page. From here, scroll down a bit and choose the cryptocurrency (or "Coin") that you would like to use, and then click on "Complete Checkout"
You will be re-directed to a page that will now show the QR code for Redeeem's wallet, the amount you need to send (in your chosen coin) and the wallet address you need to send it to. Copy the amount and wallet address and paste these in your online wallet for the amount and recipient.
MAKE SURE TO ADD A SMALL AMOUNT TO COVER MINER FEES!
You can send bitcoin from multiple wallets to this address listed above (3Aswd...), it does not need to be one transaction. For instance, if you have 0.00152 Bitcoin in one wallet and 0.00152 Bitcoin in another, you can send 2 transfers to the same address and your payment will complete.
The way it works is that Coinpayments adds all the payments to that address, and when the total amount send matches the amount required, then your credits appear.
The amount posted in this page is not inclusive of miners fees that your software or online wallet will charge you, so please add coins accordingly. Confirmation process usually takes 10-45 minutes and you'll receive an email notification so check your email too.