Did they check the rotor? This is normally the issue previous wear of the rotor can cause this, also if the calipers aren't locking the same...but then you would feel a pull.

Its likely a slider pin in the caliper assembly is frozen or binding , be sure they are lubed
properly , and move freely.

There is more than one reason this could occur. I will list the possibilities. Bad brake caliper not releasing. Bad caliper hardware, mounting pins, lack of lubrication. Brake pressure leak, example: a leak in the rear from a bad wheel cylinder can cause uneven brake wear in the front. Contamination such as grease or oil getting on the brakes can cause uneven brake wear.

The rotor on that side need to be resurfaced or possibly replaced..
Smooth surfacing on the brake rotor gives the new pads a fresh surface to brake into. Without the rotor being smooth, the flat pads will end up wearing away to the surface of the rotor and cause adverse braking symptoms

If the inner pad is wearing faster suspect a sticking caliper, or a restricted brake hose. If the outer pad wears faster suspect bad caliper hardware, also lack of lubrication or rusted caliper guide pins. If the brake pad is tapered the rotor causes that.