My DD's grandparents (dad's side) gave her a mobile to play games on which she has now become "obsessed" with. I let her play on my phone for limited periods with controlled settings so that this didn't happen but they aren't bothered about consequences (so there's no asking them to cool it, they'll just say no. Can't cut contact as it's during dad's hours).
Last time they sent her back with it and I'm not happy being responsible for it. It's quite expensive and there's no protective case, in fact I was so worried I'd have to pay for damage I bought one! She has a Leappad and so many toys I could keep santa in business, this isn't an item she needs, it's just them trying to get her one before I ever had the chance to so she favours them for spoiling her (there's backstory to back that up).
Fair enough if she was 13.... But she's 3 
Is it reasonable to say I won't have it in my house again or am I being a spoil sport?