Am I being way to nice...or people are way too rude??

I have something interesting that happened to me today, that I would like to share it in my blog.

Today, I followed my mum to Tesco S'ban 2, to stock up the weekly groceries.My mum was in a rush as she had to go to hand in the house keys to the new tenant ASAP.So, after buying some stuffs and while were about to leave, she had forgotten to buy fish and asked me to go and wait at the cashier aisle first, while she is going to buy some fish.

So there I was, with the shopping trolley, searching for the less congested aisle, as we are in a hurry and to save time.Then I found the perfect one.While waiting for my mum, I was lost in a reverie(as it was damn boring to stand there and wait for the next customer to be done) and there was this mak cik with her kids suddenly standing next to me.She was looking at me and the customer in front of me.I thought that maybe she is the wife or something.

Then suddenly, she asked me."Boleh tak mak cik beratur dulu?Satu barang je ni,"
she said with the muka tak malu and showing me of the item that she intends to buy.Thinking that she is older than me with loads of kids and she only got one item to pay(and the fact that my mum is nowhere to be seen yet), I said yes.Somehow, I know that I was saying yes for the wrong reasons.

So, with the 'muka tak malu' and a sly smile on the face, the stupid mak cik and her kids quickly cut the line and queue in front of me.I was kinda like, sentap.Dahlah malas nak beratur, muka tak malu, pastu tak kata 'thank you' (or terima kasih, if she knows English).Doesn't mean I'm young and all 'immature' like, she can pijak my kepala.Somewhere in the corner of my heart, I was cursing the mak cik and was also thinking, "Why did I say yes in the first place??".
I know that I'm partly wrong for not standing up to myself or anything, but I guess I did it with the thoughts that "Owh, she is way older than me.Tak pelah, mengalah sikit.Mak aku pun tak datang lagi.....and satu barang je kot....".The least she could do is to say "Thank you".That's all.

So, was I being way too nice to her, or was she being way too rude???