My local Sainsbo's is only a small one too, but I asked at Customer Services if they would get them in. I told them that if they were to stock them I would inform my class leader who could tell class. If we find any 'new finds' we bring in the wrappers/cans/packets for others to see and get ideas. Sainsbo's got them in for me!!
I took an empty pack into class and I know the class members have been buying them too so it's worth a try. If you don't ask you don't get x