A debt of $$1,000,000$ is being paid in quarterly payments over $2$ years, with interest of $42\%$ per year compounded quarterly. Immediately after making the third quarterly payment, the debtor makes an extraordinary non$-$agreed payment of $$300,000$ and requests that a new payment plan be presented, taking into account that the number of remaining quarterly installments remain unchanged, hoping that the amount of each one will be reduced. $.$

a$)$ Calculate the amount of the quarterly payments without considering the extraordinary payment.

b$)$ When would the debtor finish paying considering the extraordinary bonus of $$300,000?$