Disappointing service

I'm very disappointed with game,my mum purchased a defy gas stove in December 2018,due to circumstances we only got to put it sometime in May 2019. We initially called game to enquire if they could help us but my mum unfortunately lost the slip but did take a bank statement to game as proof of purchase.From the 21st of September we started having problems with out stove it kept sparking.during that week game sent out someone to have a look at the stove and they said they need a part,2 weeks later my mum had to call them only for them to say they don't have the part yet. We lost my dad a few months ago n things have already been hard,my mum cannot keep going to the store to keep asking what is being done.I don't know what to do to help the situation,I'm not sure if they waiting to get the slip from their archive. We had to buy a 2 plate stove and game knows that and they are fine with it,not making any attempt to assist us.It's disappointing as we are customers of game for many years now n the defy stove was not cheap. If you can speak to someone who knows what's going on in game or with Mrs S Narayan. Stove please contact her on ***.