I've rounded all my restaurant bills to even dollar amounts for at least a decade. When I scroll through my statement, if I see a restaurant charge that's not an even dollar amount, I go looking for the slip. Far and away the most common discrepancy is that I'll leave a tip of say $5.32 and the waiter will enter it as $5. Occasionally, they'll forget to enter it altogether and stiff themselves.

I've had a couple times where the restaurant messed it up--one was probably a typo, but they 'couldn't find it', so they got a chargeback for the difference. The other was definitely someone trying to steal; the bill was less than $20 and they left themselves a tip of $20 even. I couldn't find the slip, but pointing out my rounding habit actually convinced my local credit union to pursue it. They ended up reversing the whole charge, so there is such a thing as a free lunch.

There's one popular bar over here that messes up my tip all the time. I disputed the entire charge once and after that I always kept my receipt for drinks there. Had to dispute the tip amount about 2-3 other times after that.

Maybe it's time to start using cash. The small amount of points you get probably isn't worth the trouble.

Or stop going to the bar if they're regularly mischarging you.

Had this happen twice in three months at two different restaurants. One was a $10 difference (OK, maybe they misread what I wrote) while on vacation, and Chase credited us the amount. Just dined out and left a $24 tip on Sunday. The charge posted over $30 higher (and didn't even end in the same cents amount), as if we left a 50% tip. Filed another dispute but hoping Chase doesn't take two similar disputes in three months against me. Hopefully, having copies of the receipts and uploading them makes it look like I'm not just taking advantage of someone.