Burger King complaint: No Help,Unprofessional

I was ordering on my phone for the “Free” medium fries with a purchase of a 1$,And looking for what I thought was the code FOR THAT PARTICULAR OFFER,Which she asked for and I gave it to her,Mind you it was about 7-10 minutes To CLOSING,She then tells me “I need it in my cart”Well it was,So that being said she knew exactly what I should’ve done to proceed to check out the cart,But NO She argued About it,Verses Helping,I then just ordered a value frie and cheeseburger, no thing to do seen that they getting thrown out anyway what I said no problem mam, pull forward, again it’s not the point that it was free because clearly I didn’t have a problem paying it was the point that they getting thrown out and clearly she knew exactly what I was trying to do and still kept proceeding to tell me about my goddamn cart, Sorry that’s not really good customer service I’ve managed plenty of fast food places I would’ve just gave them knowing I’m throwing in the garbage