Is it permissible to dispose of the total deposited amount, including the interest added by the bank, or must the amount considered as interest be given in charity?

It is not permissible to contribute to this type of fund except out of necessity. In such a case, the contributor is not allowed to own the resulting interest; rather, it must be disposed of by spending it on charitable causes. As for the contributed capital, it belongs to the contributor, who may dispose of it as they wish.