Discovery Health Unfair

I am suffering with my wisdom teeth. The pain is too unbearable . For the past 3 years I’ve been with the discovery key care plan. After calling in several hospitals and dentists I've found that they will not cover my teeth removal .. so I call discovery to ask them if there's anything they can do to help or if I can upgrade my plan so that I can go and remove my wisdom teeth asap. I was told that they can't do anything I must pay cash , (which is a ridiculous amount by the way).. And I must give them 1 month notice before I can upgrade my membership!!! Upgrading for a once off treatmeant ??? The cash price is too steep and I have been with Discovery for 3 years.