Turn off call forwarding in iPhone 6s

How do I turn off call forwarding in my iPhone 6s? I have already turned it off however I noticed that it automatically turns ON.

I have already updated my iPhone 6s and even tried turning ON and OFF my phone but still it automatically turns ON. Aside from that I also tried turning off the do not disturb feature but the call forwading is still the same

Also, when I attempt to turn if off today, the circle icon (that looks like loading) only goes round and round.

Please help me thanks.