Hi Ona,
Like Ivy said, take a read of your mortgage agreement. In particular, look for (i) events of default clause; or (ii) mortgagee's right to sell
Force sale of a mortgagor's property is a serious measure and the bank should not seek it lightly. If the bank is adamant on exercising their right to repossess your property and sell, you can challenge them on the grounds of improper exercise of these rights in court. You may also need to apply for an interim injunction to prevent the bank from taking action in the meantime.
The court will generally only allow sale in extreme cases where the bank cannot cover their risk (or recoup debt) in any other way.