「嫌いを動詞にして→(嫌う)」→「To hate, to dislike」
「店員」→「Staff, Staff member」
この場合の「当たる」→「To get」
まとめて言いますと、
「I keep getting the staff that I hate.」
「I keep getting the staff member that I dislike.」
と表現します。
I had to go through the checkout of an employee that I really don't like.
この場合、次のような言い方ができますよ。
ーI had to go through the checkout of an employee that I really don't like.
「すごい嫌いな店員のレジで会計をしないといけなかった」
to go through the checkout で「レジで会計をする」
an employee that I really don't like「私がすごく嫌いな店員」
ご参考まで!