Need to vent about something!

Sorry, but I need to vent!! So I went to Sainsbury's to get some stuff. I noticed this lady was staring at me. No biggie. I moved to the next aisle and here she comes. Again... STARING! So now I'm thinking, What's her problem?! I finish my shopping and go to the tills. Of course who is there ahead of me but this same woman. She turns around and starts staring again. So I start playing with my phone so I don't have to look at her. Finally she says "I want to apologise for staring at you, but you look just like my son who just passed away." I felt really bad, after that and gave her my condolences. She said "Thank you...sorry, but I have a favour to ask. I know it's weird and I would understand completely if you don't want to, but can you give me a hug and say 'Bye Mummy' to me?" Inside I'm thinking WTF?!?! But trying to be understanding, I went ahead and did it. She smiled, thanked me, and left.
Proper awkward! The cashier rings up my stuff and the total comes out to £100.87. I knew something wasn't right, because it should have been about £40 or so. The cashier then tells me that my total was included with my Mum's. I'm like, "What?!!!" She said, "Your Mum said you were paying for her items along with your things. I told her that the woman was most definitely NOT my Mum. She said, "Well I saw you hug her and heard you call her Mummy!" fuck!!...I flew out of the shop looking for this witch, ready to get her. I see her loading up her car! She saw me and jumped in her car, I got to her as she was putting her leg in, so I grabbed her leg and as I started pulling her leg hard, it came off in my hands. So I grabbed her other leg and started pulling, just like I'm pulling yours right now!! Hahaha...