So sorry your having to wait for your sim to activate, sometimes it can happen within a couple of hours but occasionally it can take up to 24 hours to fully activate.In rare cases it could take longer due to it being the weekend or systems problems and busy periods.
Please try to be patient, it is well worth the wait when it does complete the activation process...
There may also be a barr on a replacment sim for security purposes which agents will have to remove
Please be aware that agents can take up to 24 hours to get back to you so please try to be patient. Ask an Agent. http://bit.ly/giffgaffagent