I have worked up 14672 Avios and 140 Tier points with BA. (What is actually the difference between Avios and Tiers?) Anyway, I thought this would be enough to book a flight from Oslo to London, maybe not a return ticket, but just one-way would be nice. Or an upgrade to Club Europe. But no matter what I do I always get a message saying that there are no available Avios-flights when I want to fly. I don't understand what's going on. When I check the Avios-flight calculator it says that I have enough points to book Oslo-London flights. Anyone else had a hard time actually spending the Avios, and anyone got any quickfix or suggestions?