Is the remaining amount usury (riba) or permissible (halal), knowing that it was deposited in the post office box and accrued 7% interest, and a portion of it was withdrawn?

The savings account system is usurious, so one must be wary of it. It is not permissible to take anything but the principal, and the interest must be disposed of by giving it to the poor with the intention of getting rid of Riba money, not as charity. The questioner must give away any remaining interest and withdraw the amount from this usurious system. It is not permissible to deposit money in a usurious bank except in cases of extreme necessity and if no Islamic bank exists. In such a case, one should deposit it in a current account, and if that is not available, then in a savings account, provided the interest is disposed of.