Budget analysis / spending

I’m sure this has probably been covered, but I couldn’t find it anywhere. I want to do some spend analysis - for example finding out which retailers I spend the most with, how much I spend on average per month by retailer etc. I am surprised that his functionality doesn’t already appear to be in the Curve app. I tried exporting to csv, but found that the data is unreliable because, for example, I have many duplicate transactions (for example 6 transactions for the same large sum at Amazon, so when I investigate I find that the card was declined 5 times and went through once). Does anyone have a good method for achieving what I am trying to do? Thanks.