How can the zakat for the past nine months, during which it was not paid, be made up, and what is the correct procedure for paying zakat in the coming year, taking into account the wealth that was not previously zakated?

You must investigate and review your statements carefully to ascertain the true date for paying Zakat, as delaying Zakat after it becomes due is not permissible. What was paid out the first time was for the first year, and what was paid out this year is for the past year. It is as if in both years you are delaying the payment of Zakat beyond its due date. So, when Rabi' al-Akhir comes—i.e., in three months—look at the wealth you possess and pay its Zakat. Then, be diligent in the future to pay Zakat when its due date (hawl) arrives in Rabi' al-Akhir, and do not delay it. Alternatively, you can pay your Zakat now and establish the hawl for your wealth in Muharram.