on top of sth

in addition to something, especially something unpleasant

除(尤指令人不快之事)之外(还)

We missed our flight, and on top of that we had to wait seven hours for the next one.

我们没赶上飞机，而且下一班还得再等七个小时。

Not just the horrible, vicious act, but then on top of that the refusal to even admit the horrible, vicious act.

他们不仅仅做出了可恶、恶毒的行为，更糟的是，他们还拒绝承认那可恶、恶毒的行为。