Telangana State Road Transport Corporation [TSRTC] — Regarding child ticket

Address:

From L.b nagar to choutuppal (Surya et Depo)

I'm traveling with my family from L.b nagar to choutuppal. I have 3 year girl and 4 year boy who is yet to celebrate his 5th birthday. He' is born on 31/03/2018.. RTC conductor asked the age the same has been conveyed to him. But he is charged half ticket for my son...What I clearly know is the child below 5 years should not be charged any ticket...and let me know if I'm wrong regarding the TSRTC rule..
Bus conductor behaved very badly with me. Bus No. AP24.E 0088. However I have taken ticket for my kid.
Attached the ticket as well..