McDonald's The Square Hatfield cashier woes

I went to McDonald's at The Square in Hatfield (One I usually visit) on Friday October 19th at around 23H00 in the evening and I received the worst service to date. As per usual, I buy my meal; Two large Big Mac meals with extra salt and pepper (paid) for myself and a colleague and when the order arrives, I find two regular size fries in my paper bag after a longer wait than usual (which I was actually only opening to check my requested extra salt and pepper). Now I point this out to Lucia (the cashier who took my receipt and gave me the meals, who was not the one I bought from initially) and she gives me a not so bothered attitude at which I then mention to her that my drinks are clearly large sized but my fries regular. She takes the fries with no regard to me whatsover as well as no apology and she disappears (to the kitchen I assume) and goes on chatting to her colleagues while myself and few other customers wait and wait. Finally, she reappears without my fries and proceeds to help other customers so I ignore this and wait my turn. She disappears to the back once again (did this three times or so). She then reappears with my fries which are not filled up to large quantity serving and toses them on the counter and quickly turns back to walk away to the kitchen (Mind you I'm waiting to tell her about my extra salt and pepper), so I wait even longer. She reappears again twice seeing that I'm still waiting and staring at her as I signal her and she turns back to the kitchen (twice). When she reappears the third time, I interrupt her as she's about to attend another customer who arrives while I was waiting (yes, she ignored me to attend to that customer) and I tell her about the extra salt and pepper I'm waiting for (which I paid for).

She asks to see my receipt (which she took), so I point out to her that she took it and she looks at me and asks if I paid for it which I rep**** "yes" to. She then calls the other cashier (the one I bought from) to ask if indeed I paid for the salt and pepper and she proceeds to give me a funny look with attitude and disregards me and walks away. I had to wait for the other cashier who was also busy to and assist me (all for small packets of salt and pepper guys).

She (Lucia) reappears while the other cashier is still assisting customers in the buying queue, talks to the other cashier in her their home language because I look foreign and she assumes I couldn't hear. She speaks disregardingly of me because I'm waiting and staring at her all for salt and pepper which then proceeds to grab and toss my direction disregardingly (with an entire queue of customers watching) and proceeds to walk away just as I was actually considering bringing her to order. She disappears once again.

I dislike every little bit of interaction I received from this Lucia lady and the manner in which she served me. I will not rest until she is dealt with. No respect for customers and her occupation whatsover!!