How to say "这玩意儿哪来的诚意啊" (zhè wán yì ér nǎ lái de chéng yì a) in Chinese dialogue

zhèwánérláidechénga

Where am I supposed to find the sincerity in something like this?

Idioms & Colloquial Expressions
Grammar Patterns
INTERACTIVE SCRIPT TIMELINE
LINE 0139:28
shuō
fēi
shuō
rén
jiā
méi
yǒu
chéng

He kept saying there was no sincerity.

LINE 0239:30
PLAYING SCENE
zhè
wán
ér
lái
de
chéng
a

Where am I supposed to find the sincerity in something like this?

LINE 0339:33
gēn
shuō
a

I'm telling you—

Show Information
Source MediaTV Series
Season & EpisodeS1 E15
Timestamp39:30
TMDB ID272681