Can we charge gst under rcm

we have entered a contract with a goods transport agency, provided a clause that if vehicle wont for 4000 minimum kilometers in  a month that part we will pay for 7.50 rs for that short running. 

for eg. 340 short run in month then 340km*7.5/- =2550.

now my query is that, i am liable to pay gst on RCM or not.

because no actual service is provided by the transporter.

can anyone pls reslove the issuse..

regards,

mohan