Is it permissible for an employee to benefit from the medical insurance paid for him by the company, knowing the impermissibility of commercial insurance, or should he seek treatment at his own expense?

It is permissible for an employee to receive medical treatment at the expense of a commercial insurance company to the extent of what their company has paid, because it is a grant from the company to its employees. As for anything beyond that, it is money acquired through a corrupt contract, and it is not permissible to deal with its owner in this regard. "And whatever existing usurped money or money acquired through contracts that are not permissible upon acquisition, if a Muslim recognizes it, he should avoid it."