I managed to sort out sending back the GBA and paying for the Sonic jacket today, so that was something, at least.
Update: No I didn't. I cocked up. I appear to have left Puyo Pop in the GBA, when I sent it away. I'm incredibly great, me! Still, I've informed the guy who I'm getting a refund from, he laughed about it but will return it.
Er, now all I have to do is hope I did actually leave the game in the GBA.
Off to Nan's again tonight - that'll be nice. I'm gonna sell that copy of Golden Sun 2 I've not been able to get into at all, as well.