FS-51 Help Please

[Hybriid]

Hi, I currently have a G&G FS-51 and my problem is that the screw/ pin that goes in the mag release button has fallen out which means that the 'retaining clamp?' on the opposite side falls out, therefore I have to manually put the 'retaining clamp?' back in to get the magazine to stay in which means that whenever the button is pressed or if the gun is slanted at all it all falls out :S

I was just wondering if anyone knows where I could get a replacement part from or could help at all

Cheers!