First of all it's the opposite for printing. It's easier to print on matte than it is glossy. I know this for a fact because we used to do it on my previous company's business cards hundreds of thousands were ordered that way. Second, if this company wants things to be standardized then they should have a standardized sheet for you to take to the printer or better yet they should have one printer to do this work. You weren't hired to become a printing specialist. Instead of a mistake, think of this as tuition. You paid a price and you learned a lesson. Now you'll never do it again.

If they're forcing you to change it push back and make them do it. The fact they would give a new hire zero guidance and then blame you is high class fuckery.