Lebara phone number hasn't changed for texting after PAC code used

I've just joined Lebara and brought my old phone number across with a PAC code but when I text it comes from my Lebara number. Any ideas of how to change that to my old phone number?

ScubaMum this is probably happening because the porting process is still in effect. It's been a while since your post, is the issue still happening or is your ported number now working?