Orange rip off

I bought an Orange moble phone on friday and got ripped off for £20, as this could well happen to you as well take heed!
It works like this, if you buy a pay as you go Orange moble and want to keep your old number, what orange do is to add the top up you have to buy at the same time as the new handset (no option here) to the new number , not to your current number, they then delete the new number (and your top up) they will then tell you theres no trace of the money and that it's your fault for deleting the new number, although you have no control over this part. This seems to be a fairly common scam as far as I'm able to find out, my advise, don't use orange! Wayne