Wrong name on my driving licence & Passport...?

I had never noticed this before, I just assumed it was how they did it but after applying for Finance on a new car and getting declined because of it I've been told I need to correct it.

On both my driving licence & passport my name is down as Lee-Garry. I thought this was just how they laid out middle names (my first names Lee middle Garry) but after someone pointing it and out checking its not, they have got me down as my first name being Lee-Garry.

I have no idea how this has happened.. my Mum filled the forms out when applied for these as I was still at school and she swears she wouldn't have put my name down like that (she done my brothers forms too and his are normal).

Anyway, so now apparently I am classed as being two different people.. how the heck do I go about getting this corrected?!