Ok yeah I just did the same thing, went into the orange store asked about panther and the guy said to phone up and they will swap me onto panther no problem.
Just rang orange now and with no fuss the woman has swapped me from
Dolphin 30
500 minutes
3000 txts
unlimited internet (500mb)
TO
Panther 30
400 minutes
3000 txt
unlimited internet (5gb FUP)
free orange sat nav
and something about free picture messages
No charge and I was impressed by how simple and fast this was to do.
