Since you appear to be a Skymiles member, why don't you credit your Avianca flights there instead? That is, unless you're flying Avianca enough that status with them would make a difference.

I have a friend who is based in the UK but regularly ends up on Avianca flights, mostly domestic, and he has had very little problem crediting AV flights to Flying Blue, without having to follow up. I'd imagine it'd be similar with Skymiles.