It's very frustrating when that happens.
Most balancing machines can be set to a round-over function, so that any imbalance less than .25 ounce is rounded to zero, or the next higher. It makes the machine read "0.00" which if the customer is watching, pleases them more. But it can allow an imbalance to pass.
Ask if that's done at Discount.
Both tires should be released from the bead, spun 180 in relation to the wheel, and then rebalanced.
New tires will reveal small problems with the alignment - the old tires wear in to the progressive wear that the steering achieves, and hides the fault - to a small extent.
Hope you get it corrected.