The property service of the flat I stayed in last year (for my 2nd uni year, not official uni accommodation) has paid me my deposit back, but has allegedly given me 2 lots of payments ( the deposit is £650 so they've given me £1300), but the person in charge told me this was a mistake and I have to pay them back £650 which isn't mine.

The thing is, this is an illegal property service (but they're 'untouchable'), they are pretty dodgy tbf and I don't actually know if they have given me 2 lots of deposits (because I haven't checked my balance because I'm scared of how much money I might not have, I'm also worried I won't get Student Finance next term because I applied late).

I know obviously the first thing to do is check my balance and see if they're telling the truth or not.

But being told I've been payed back 2 loads of my deposit, and knowing that they're a dodgy, illegal property service (though they don't look illegal), would I be wrong in thinking this seems a bit fishy? I'm a bit stressed today sorry if this doesn't make any sense.