I recently asked for a PAC code from Orange PAYG to move my number to another provider.
After a 20 minute wait, I got through to their retention team. They gave me an amazing offer, can't remember exactly what the deal was but after I mentioned I was moving to ASDA mobile (8p/min landlines, 8p/min mobiles, 4p per text) it was something like ...
5p per text
10p/min mobiles (might have been 12p/min)
some free evening & weekend deal (might be to other orange phones)
possibly some free texts
I wasn't listening very closely because I was moving that phone number regardless.