Turning auto renew off

Good day. I would like to know how can i turn the auto renew off. All my clients is on a difrent speeds but uncaped. There account is for 30 days but when the 30 days expire zima auto renew them without me. But some of the clients have not payed and only when i do a recon on the bank statments i notice some of my clients havent payed for 2 to 3 months but the intenet is still active for them. Is it possable to make some screen shots on what to turn on or off.

Please help.