Vodacom threatens to take my number if I don't upgrade

So I just had a call from a sales agent threatening if I do not go upgrade my contract and if I go on pay as you go I will lose my number which I use for business. Any lawyers out there? Can they threatening me like this? Will post on other sites as well seeking legal advice! She said due to country economics i must upgrade or pay more to stay as is ir if I go on pay as you go then I lose my number