Not Able To Get A Good Read On That Offer

I’m in the first window of the drive-thru. I hear the ding indicating a customer is at the speaker and answer it.

Me: “Hi, welcome to [Restaurant]. What can I get for you today?”

Customer: “Hi. I have this coupon and I wanted to know if I could use it for iced coffees?”

Me: “Okay, ma’am! Could you read out the coupon for me?”

She reads mostly stuff I can’t hear due to the quality of the speakers and the multiple cars.

Customer: “…iced coffees.”

Me: *Dying a little inside* “Okay, ma’am, yes, you can use it for an iced coffee.”

Customer: “Oh, lovely. Could I get a large or can I only get a medium?”

Me: “Well, what does the coupon say?”

Customer: “It says, ‘any size’.”

I’m resisting the urge to bang my head against the metal shelving around my register.

Me: “Yes, ma’am, you can use it for a large.”