Missing roller blind fitting what can I do?

I bought roller blinds in Ikea yesterday. I got them home & only just noticed that the fitting is missing on one side (not the one with the pull up string).

I've got a guy coming around tomorrow at 9am to fit that and another blind. Ikea isn't opened to 10am & it's a 20 minute drive away so won't be able to get it on time. I need these fitted tomorrow as family coming at the end of the week.

Can I buy fittings separately in Tesco? or another supermarket? I can get to these easily in the morning or Argos???

HELLLLLPPPPPPP

I wouldnt have thought it was something a supermarket would stock, but I think whatever you will have the same problem that the shop wont be open till 10 because its a bank holiday. Homebase is a possibility, if you have a local one. You could check Argos online, but I suspect they are more likely to have just the ones that come with the blinds?
Sorry I cant be more help!

Ring the blind guy, he may have a spare on him otherwise re-arrange another time for him to come when you've had chance to pick up the missing piece.