Can you say which supermarket it was?
First, don't worry about it, the 12 month ban nonsense is just that, nonsense. It's a scare tactic that they use. Go back in three months and they'll have totally forgotten about it. they also won't call the police. You'd need to be a repeat offender or to have stolen something big. Plus they would need to have called the police straight away,
Second, if it was me, (or my wife it happened to) I'd raise hell! Not only would they be getting a strongly worded letter they'd have me picketing the store and having calls to their CRM manager in their head office on a daily basis.
I'd probably also use every medium I could to advertise the fact that they simply picked on someone vulnerable to make a point.
You could leave it, nothing more will come of it but on principle I wouldn't be able to
You'll probably find that a good letter with the threat of going public with what you feel was an attack on a vulnerable women will get you an apology and a voucher. (Depending on the store) If you use a Nectar card or a similar store scheme such as a Tesco loyalty card make a note of the number and show how much you have spent in their store over the years. Let them know that as well. They don't want any bad press or to be bad mouthed by a mum, most of the large supermarkets are very sensitive to that kind of thing.
Here's a funny story to cheer you up. This happened to me a few months ago.
I went to a large Sainsburys one lunchtime to buy a bottle of red wine for that evening. I was going to be home late and wouldn't have the chance later. This is also my local store at which I do all of my shopping.
I got to the till to pay.
Till person: Do you have a passport?
Me: Erm....what?
Her: I need ID to prove your age
Me: Strange that you would ask for a passport, I don't happen to carry mine around.
Her: Well do you have ID?
Me: No but I'm 30 years old! I'm in a suit, I look 30.
Her: You look under 18.
Me: Well thanks, but I'm not. Do I look older than 17?
Her: Well...yes
Me: but not 18?
Her: No
Me: So 17 and a half?
Her: Maybe
Me: I don't have any ID but I do have 5 credit cards with my name on
Her: They could be your dad's cards
Me: This is getting silly, You won't serve me? Okay, I'd like to speak to your supervisor
Supervisor arrives
Him: What's the problem?
Me: How old do I look?
Him: 25-30
Me: Well she thinks I'm under 18, could you please sell me this bottle of wine?
Him: No, I have to support her, I can't overide her
Me: SO WHAT'S THE POINT IN BEING A SUPERVISOR?
(I was getting angry at this stage
Him: You could try another till to see if they will serve you.
Me: WHAT? So I could try every till until one of them serves me?
Him: Yes.
Me: Do you not think that's a bit silly?
Him: Well...
Me: Could I speak to the store manager please?
Now please remember that I spend a lot of money in this place, I have never been turned down before and it's not like I was buying a can of diamond white to get drunk on. It was a £15 bottle of wine.
The store manager arrived. I told him what had happened. he aplogised as he saw that the situation was a bit silly. He said I should try another till! I said that I would come back later, with 50 photocopies of my passport and I would like him to put a copy at each till so that I'm not going to turn up at his supermarket and not be served. He said that he wouldn't do that but saw that the situation was a bit silly.
As an apology he would let me get a 6 bottle wine carrier, choose any 6 bottles of wine and have them for free. (I think he realised I wasn't likely to leave until the problem was resolved)
Not a bad result. Complaining does work sometimes
I'm not usually as abrasive as that but I shop there almost every day, I spend a lot of money there and I don't want to go in not knowing whether I'll be served or not. I've actually turned into good friends with the guy, whenever I see him we have a little chat and laugh about the situation.
Of course technically the store was right to refuse me. I didn't have ID and the till person was unsure. But sometimes policies are enforced with little thought and without putting the situation into context. It sounds like the same thing has happened to you.