@Moderator_2
Thanks for the response! I figured out that symboltoken which I was passing on was wrong. And due to which no data was returned.
But as problem was overlooked, it took a lot of time to determine whether the problem was at my end or technical glitch at your end.
Probable modifications which I can think of:
Validate the data before further processing - and if something is wrong, return a graceful message to the calling user.
If there is a technical glitch, also inform users accordingly.
Clarity in the responses will save a lot of time for end users.