Dynamic pricing can be considered a key method for the smart grid which maintains a balance supply and demand with the help of a closed-loop super twisting sliding mode controller (STSMC). Demand-side load management (DSLM) consists of agents that control, change, shift and modify the load usage pattern according to dynamic pricing offered by the smart grid. The DSLM agents under price-based DR programs perform load shifting, peak clipping and valley filling to maintain the balance between demand and supply. A control theoretic approach is introduced in this work for persistent demand control by dynamic price-based closed-loop STSMC. A renewable energy integrated micro grid platform is discussed to show that the demand of consumers can be controlled through STSMC which regulates the electricity price to the DSLM agents installed in smart meters at the demand side. The overall demand elasticity of the current study is represented by a first order dynamic price generation model having a piece-wise linear DR program and uncertainty of 1MWh is added in overall demand response of the system to make simulations more realistic. The simulations validate that STSMC is a useful technique to control closed loop elastic demand and preserve a balance between demand and generation in renewable energy integrated micro grid.