Is it permissible to buy work shoes with company money and then use them personally or sell them, while bringing a personal pair of shoes for use at work, and is it permissible to take future amounts allocated for buying new shoes for employees?

If a company gives money to an employee to purchase something for work use, it is not permissible for the employee to keep it and use an alternative, because it is a conditional gift and its condition must be adhered to. This is similar to someone giving money to buy a turban or to enter a bathhouse; it must be spent on what it was designated for, if the giver intended that. Therefore, the new shoe must be used for work unless the company permits otherwise. If the company disburses new funds for other shoes to those who previously received them, there is no harm in taking it if the condition applies to them, such as the spoilage of the first shoe or the need for a new one. Nothing more than repentance and using the first shoe for work is required. There is no harm in taking money again to buy a new shoe, unless the spoilage of the first was a condition.