갈수록 태산이다 / 갈수록 태산이네요
things keep getting worse; out of the frying pan into the fire
Example
문제를 하나 해결했더니 갈수록 태산이네요.
I solved one problem, and things just keep getting harder.
Word parts
태 great+산 mountain
Literally 'the further you go, the bigger the mountain'.
Good to know
산 넘어 산 'mountain after mountain' expresses the same frustration.