From all the info on the Oneworld Explorer ticket, I`m pretty sure the answer to my question below is yes, I can do it, but I wanted to get a second opinon...

I just called the BA office in Bogota about this. I originally flew from London to Lima. Then I was supposed to have a flight from Rio to Santiago but I now want to change it to Lima to Buenos Aires (with LanPeru). They said I can`t do it because I flew into Lima orginally and can`t fly back through it again.

But I was also supposed to have a Cusco to Lima flight before, why was that flight allowed and this one isn`t (as I would be flying back through Lima in that case)?

Bit complicated but I basically want to know if you can fly back through a city more than once on a Oneworld ticket?