When we put forward a recommendation, we would calculate the expected savings based on your past usage and our understanding of your future plans. When we calculate the actual savings, say after one year, this is based on actual usage so your savings are calculated precisely, based on the actual number of kWh consumed and the number of call minutes you have made. Therefore any changes in your usage are accounted for precisely.
Please note that in certain circumstances, our recommendation would lead to reduced consumption, which would result in a saving.