I get around this dilemma by religiously asking for receipts and entering the transactions into my DIY Filemaker Pro database as soon as I get back from the latest shopping spree. I keep the receipts and reconcile the DIY database balance against my account balance there and then. It takes about two minutes per week.
For online purchases in local or foreign currencies (usually USD or GBP) I create a transaction as soon as I get the order details via email, using the order/invoice number as a reference field. I pay Amazon in GBP knowing that after delivery there'll be a €0.45 currency fee posted against the original euro transaction amount, so no surprises
The key is the discipline to record the transactions there and then as
@Steven Barrett said in another thread. Once I got into the swing of things 12 years ago its now second nature to me, like locking the doors, feeding the dog, or taking my meds (I started the amnesia meds 12 years ago!)
I pay insurances and other stuff (car, house, dog, broadband, phone, TV, etc) on the drip mainly via my bank as the insurance broker, free of finance charges. At the start of each insurance/contract period, I prepopulate the database with transactions dated and valued as they will fall due and am on it like white on rice if the money doesn't get taken. Same with payments from a variety of sources, pensions, etc; if they're not there when I predict, answers will be demanded. There may be slight variations in the payment dates I calculate due to weekends/bank holidays; my little algorithm ain't AI'd enough to take account of those, KISS being the operative word.
Unless paper receipts are for warrantied items, they get burned/shredded depending on the time of year; receipts for warrantied items get stapled to the instruction manual and filed.
I'm now using the LIDL Plus app on my phone with digital receipts, thanks to
@ClubMan. I'm working on extracting the details from the receipts to analyse food-spend vs middle-aisle purchases. I bought yet another desktop lamp yesterday for €7.99. I can't help myself!