Device has saved us nothing in regard to our Elect

My Sister in Law bought this device which she had installed to save on her electricity bill. To date she has not<br> save a cent.. She has signed a contract the company and would like to know if she can cancel the agreement.<br> <br> Her Cell no is *** and her name is Jenny Claasen, or you can email her on [Email Removed] as she will be able to supply you with more details<br> <br> Many Thanks