I have a similar problem. It's got to the stage where I refuse to buy cream (Single, Double, Whipped) now. The supply of Fresh Cream here(and it has to be Fresh rather than UHT? but some cunningly call themselves Fresh LongLife Cream to confuse the issue even further), is rather hit or miss and if the one Mrs EoA wants isn't available I've no idea which is the best alternative.
I guess I'd be pretty p!ssed off if I sent her out for a case of Old Speckled Hen and she came back with a case of Stella.