Totally theoretical situation.....

Lets say I have my home line and Internet with Vodafone...... I then join the Xnet Fusion plan and tell Xnet not to worry about porting my number, Ill take a new number. They swap me over and all is running well with a new phone number via Xnet etc...

Then a few days/weeks later I go "oh crap, I NEED my old number back for xxxx reason".

Is it actually possible to get that number ported to Xnet Fusion although the original port/number has been "thrown back" into the pool ? (Obviously assuming Telecom hasnt assigned it to someone else).