What if users could press the merchant logo of a transaction and press a button, say “Report inaccurate logo?” or even “Report inaccurate merchant name”.
It would then open a dialogue with some options, e.g. “What is inaccurate”, and then a few options, e.g. “wrong logo, too much zoom, too little zoom, Something else, etc.”.
And then perhaps even give users an option to upload a more correct logo, or send a URL to the official logo file, etc.
Afterwards, the new data should be presented like Google Maps Local Guides: Show the users that frequently interact with the particular merchant a dialogue: “We can see that you have a number of transactions with ‹merchant_name›. Other users suggested these logos. Which do you think is more appropriate?” and then a number of options, including “Skip” and “Never show me again” options.
Because, I mean, why even have merchant logos when most of them look like ****?
EDIT: And no, I do not advocate removing these logos. Logos/images say more than a thousand words and, moreover, the brain cognition involving visuals is many times more efficient than recognition of construed meaning, such as words and sentences.