Purple shampoo is for toning yellow hair not orange. You need a Blue to counteract the orange colour. (Opposites on the colour wheel)
I'm not keen on DIY colour removers like ColourB4 but if you've used an oxidising colour, it will remove it. (It's an oxidising colour if you had to mix two solutions together before applying it). The MOST important thing is to agitate the hair constantly when rinsing it and use a timer to ensure you rinse the hair for at least 5 minutes. If you don't rinse it enough, any colour left behind will re-oxidise and become orange again. Do not be tempted to re-colour it yourself afterwards though.
Also, make sure your hairdresser knows you used this product.
Hopefully, she's a decent colourist who understands how this product affects any colour she subsequently applies.