Your internet should work soon, probably tomorrow.
The reason is when you port your number you have to wait for all features to come over aswell, sorry.
Also you can message a educator about the Ask an agent error, they can fix it for you.
Here's how to giffgaff an iPhone 3gs. -http://bit.ly/giffgaffiphone
There is a known issue with some accounts and ask an agent. Contact an educator, and they can get it fixed for you http://bit.ly/giffgaffcontacts