Can they accept credit card to place the 12k booking ? I heard my friends said 12k is non-refundable but not sure what is the criteria, mind to share ?

For this project, u just need pay rm12k booking fees, and 3% balance on first payment (their discount is
7+4+1+3% discount)
And on the stage 2(b) which is around 25% construction period,exsim will give u back 4% , and continous 1% and 3%.

Eventually means ur rm20k (around this figure) will stuck with exsim until 25% completion which could be around 1 year from now .