I also tried to order the Aviva strips instead of my Freestyle ones and got told that they are not on the NHS. I thought that can't be correct so queried it with my pharmacist who said it's a load of rubbish and of course they are. I then rang Accu Chek and asked for the pip code. Hope I'm not going to have the same trouble as yourself :roll
I get Aviva strips on prescription they are available on NHS prescription