Gotcha - Charity Bags!

This morning I saw someone pushing a charity bag through our letterbox, so I found the key and opened the door.  Just down the door I found the young man who had delivered it.

If you have read my previous posts on this you will recall that my wife put this notice on the door:

"No more charity bags, please," so I asked the young man if he understood English.  The answer was a blank stare, so I opened the charity bag he had just delivered, turned it inside out and put the bag it was in inside it.  I then opened a bin and made a pantomime of throwing it away.

In fact, it's now under the sink waiting to be filled with our rubbish.  Would it be a good idea to remove our notice, as the deliverers don't seem to understand English anyway, and just keep the charity bags as binliners, which we do anyway?

Which brings me to another point:  In my car I keep shopping bags so I don't have to use the supermarkets' plastic bags - but I always forget to take them into the store.  Therefore we have a mass of these at home.  The problem is that the stores won't take them back as they've been used, but we need some way of recycling them.  Who would use these plastic bags? 

What I should do, of course, is just to refill the trolley with my shopping and pack it into the bags I have in my car, but I don't do so as sometimes it's raining at other times I don't feel I have the time.  However, it still doesn't solve the problem as to what can be done with all the bags we're collecting.  Any suggestions?