There is no such way to transfer credits
You cannot add Facebook Credits for free. They must be purchased with a credit card or via PayPal to Facebook. They do occasionally give away free Facebook Credits though.
Just buy it on Paypal
You can pay with your creditcard, paypal, or your phone.
You need to deposit your Alertpay into your checking account and then transfer from your checking account to Paypal or vise versa
Send an EMail to facebook, or send them a letter asking them to transfer the credits. Look up Facebook Headquarters address and info on google or yahoo, and you'll probably find it.
Transfer to your PayPal. Then from PayPal you can transfer to your Account Bank.
If you go to Account in the top right corner, on mine there is a drop down option of Credit Balance and in parenthesis it tells me how many FBC (Facebook credits) i have. If this doesn't show you, go to the help center and choose the option credits.
You can get coins by purchasing it on DDTank Zong but apparently Zong is already gone so you need to buy from facebook credits or paypal.
You need to use facebook credits,paypal or sell things to other players, there is zong for mobile but it's gone now :(
You earn facebook credits by playing lots of games and apps on facebook.
If you want facebook credits you need to pay for the credits. I'm so sorry!