Walk in with 4-6 friends, grab your rims and walk out. Don't even THINK about justifying your action let alone paying for whatever the hell they did. Hell if you need an extra pair of hands I'll go with you. This isn't the first time I am hearing something bad about Rim Techniques.
Later on DIY them. There are plenty of those around. All you need a nice afternoon and 1/4 of the price to polish 1 rim on materials.
Selling: Winter Tires/Wheels for E36/E30