Dial *118*1*5# ->Call
Then choose 5 Stop auto renewal
If you fail to find the page above .try the following way .
*118*# then press call
Select the current plan that you are subscribed on
Then select "Stop auto renewl“
If your have insufficient balance or your account is in a passive period. You doesn't need to do anything as u mobile will fails to automatically renew, but there will try to renew your subscription again on the following day.If you not wish to continue to subscribe to the plan . wait for few day or try the method abov to avoid auto renew .