Welcome to our forums and thank you for getting in touch. I'm sorry that you've been having trouble trying to change your landline setup, we can certainly look to help you out with this.
I've had a quick look at the backend of your services and it doesn't seem like you have permanent number conceal provisioned by us. Could this be a setting you have changed on the handset itself? If so, it may be worth taking a look at the instruction manual for your landline, or having a quick search for the model number online if you don't have the manual to hand.