No need to load up prepaid credits. all you have to do is register the codes below during the promo period. Make sure you have enough credits to register.
Extra Call & Surf 20 - 60 minutes of calls to smart/tnt + 60 minutes of mobile internet
Text EXTRACALL to 8998
Extra Alltxt 30 - 1000 texts to smart/tnt + 10 texts to other networks
Text EXTRATEXT to 8998Promo will be valid on May 21-22, 2011 only.
From Smart