In Australia we recently had MEGACASINO offer.
register - depoist $20 and receive 4000 WGT credits.
Did all the above, saved screens of the process, found all the ocnfirmation emails in my Junk Mail...
Played with my $20, lost it all.
Waited the allocated time before contacting support.
contacted them with a copy of email on Deposit Confirmation, a few hours later, got the credits.
Screenshots, screenshots, screenshots. CYA! (Cover your A$$)
Previous Casino offer a whil ago also paid out, but that time i actually won $100+ on the tables, so great value.