Trai — airtel landline

Hi, i have been using airtel landline from more than 15 years.
From past few months airtel is charging me for customer care numbers (Uan) starting from 1860xxxxxx under a tag of premium numbers. However, the charges are for a local call.

I am having unlimited calling plan with unlimited free local & std calls.

My complaint is when airtel is giving me unlimited plan why they are charging for such numbers additionally when they are treated as local calls.

I am also having vodafone postpaid and tried it in other service provides having unlimited calling plans, no operator is charging separately for such numbers. Only airtel is charging for them explicitly in unlimited calling plans.

I tried to complaint airtel customer care, nodal officer and appellate authority but they are unable to share me any such trai guidelines for charging such numbers to customers. They also was saying that we are airtel and its their business guidelines to charge for such numbers.

May i know from trai, if there is any guidelines to charge for such numbers in unlimited calling plans? Why companies like airtel is charging explicitly for such numbers in unlimited plans.

Please help.