Sharing my experience
Port out from digi prepaid to hotlink prepaid

Day1:
Went to maxis centre to get new sim card 10am
1pm Digi sent sms, replied yes
8.15pm Digi said unsuccessful

Day 2
8am Call digi, Digi ask me to call maxis to resubmit
Call maxis to resubmit request
12pm Digi sent sms, replied Yes
*My balance was RM1, I topup RM5 just incase
8.30pm - Phone no more coverage
Change to new sim card - success