I divorced my wife, a British Muslim, with a revocable divorce on 18 February 2006 and I have not taken her back since. She is elderly and menopausal. What is the legal ruling for this?

If the case is as mentioned in the question, and the husband made a one or twofold pronouncement of divorce and the waiting period ended, he cannot take back his wife except with her consent and a new marriage contract.
The waiting period for a menopausal woman is three months which, in this case, have expired.
God Almighty knows best.