Antera Kitchen And Bar — Charging separate 5 service charge on bill

Address:

Jubilee hills, hyderabad

This is eswara rao and kishore, we went antera restaurant In jubilee hills, hyderabad,
We didn't check bill, we paid total bill rs 5962/-, over Lookingly they charged extra service charge 5 ℅, they mentioned optional but they added in bill, I think that one GST, but they charged illegally 5℅ service charge extra, no one notice in hurry,
Why they adding gst 5℅ and service charge 5℅, they took in total bil rsl 271/- extra, service charge without inform, my concern to remove personal service charge on bill it's illegal