You may have a situation that is really difficult and can not be consulted to any kind of company, such as issues beyond your control, let say.. some kind of tree roots that penetrate the sewers, the installation of drainage pipes are damaged and so forth.
Well.. An expert who is provided for you to give advice on how to control or fix this problem. No longer need to worry. Any type of preventive maintenance provided by the company can help you. You doubt with the information I provided here? Then ask directly to them during your consultation via phone, especially if there is a cost for certain services that applied to you.