All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu 'alyhi wa sallam, is His slave and Messenger.
First of all, you should know that it is not permissible to solve one's problems by resorting to man-made laws while there is an Islamic court, unless there is no other alternative to get one's right or repel injustice.
Besides, you have to know that it is not permissible to get married to another man since your husband did not grant you a divorce, as he still considers you as his wife by saying that he will not divorce you until there is a court order to that effect. [This is what is stated in the question]
Since the case is as you have mentioned, that the Islamic centre ordered your husband to divorce you but he refused, then we consider that you should seek advice from the brothers who are running this centre, if they advise you to take your case to a civil court in order to remove the harm from you, then there is no harm in resorting to such a court, if Allaah wills. The scholars stated that if there is no Islamic justice in order to get one's right and repel the injustice, then one can resort to any institution or authority through which one could get back his right.
Al-'Izz Ibn 'Abdus-Salaam said, “If non-Muslims take over a huge land and put the justice in the hands of some non-Muslims who would run the interests of Muslims, then it appears that this is permissible in order to achieve the general interest of Muslims and repel the harm from them.”
We ask Allaah to relieve your sorrow and make a way out of your difficulty, and whoever fears Allaah, Allaah will suffice him. Allaah Says (what means): {… And whosoever fears Allaah and keeps his duty to Him, He will make a way for him to get out (from every difficulty). And He will provide him from (sources) he never could imagine.}[Quran 65:2-3]
To conclude, it is not permissible for you to remarry even if your husband gives you permission to do so since the marriage contract is still in effect between you two, but if he divorces you or there is a court order that says that you are divorced, then in this case you can remarry when your waiting period expires.
Allaah Knows best.