Find the matrix $A$ of the linear transformation $T(z) = (3+6 i)z$ from ${\mathbb C}$ to ${\mathbb C}$ with respect to the basis $\left\lbrace 2 + 4 i, 4 + 3 i \right\rbrace$.

$A=$ $\left[\Rule{0pt}{2.4em}{0pt}\right.$$\left]\Rule{0pt}{2.4em}{0pt}\right.$