Is there a good way to automate importing data from an external client who, unfortunately, doesn't always provide a consistent format?

One of our more active clients at work provides a data file in xlsx format multiple times a day, which I import into my model in order to process a bunch of calculations. The data file itself is quite small, usually up to 20 lines at most. However, it's formatted quite terribly and depending on who sends it can extra columns for no reason. It also has extra empty rows with data in just one cell in the middle sometimes. I have resigned myself to just pasting it in each time. The other issue is that this data forms part of a rolling total on my end, so power query would wipe the previous data if I tried to import it normally.

I'm decently handy with both power query and VBA, but I have never been able to figure out a good way to deal with poorly formatted data. Any tips?