Ran out of data - need a bit (mostly for maps) to tide me over for the final week

I have never run out of data before, I barely use it as I'm almost always somewhere with wifi or not using my phone when I'm out and about much except for maps and google searches... Somehow I have run out this month (maybe something was running in the background??)

I would greatly, greatly appreciate any you could send my way!! Thanks a bunch!