Misery by game krugersdorp

I bought fram 140 inverter welder online from game store on 6/01/2021,the inverter was on discount.On 8/01/2021 game deliberately dispatched and delivered wrong fram 120 inverter.I opened it and used it as i set power i realised it was 120 Watt not 140 watts.Now after notifying game krugersdorp about their mistake,they said they wont take it i opened it.They take my expensive item money for useless cheap and less power item.