Voltar electricity saving device not working

On 18/01/2018 this company installed a Voltar electricity savings device which is supposed to save up to 50% of elect consumption. From the 1st week I saw NO savings. When I phoned them, they said to give it another week...again No saving. The electrician has been out 3-4 times to "adjust" the box, he changed the box 2x, and NO savings. This has gone on for 2 months, I asked them to remove the box and give my money back, to which the manager, Shaun, rep**** they would remove the box but not refund me.