Bharat Petroleum [BPCL] — call from gas agency

Address:

Plot No E/7 ; shalaka row house, sector 12, Kharghar, Navi Mumbai, Mumbai City, Maharashtra, 410210

People are calling from gas agency to check the condition of gas pipe and other details.
They are saying it's a paid service whereas this should a regular checkup while your person comes with the refill cylinder..
Why such extra burden on the customer. P
Kindly let me know if such checkups are paid or free