In my area the postman will usually try various neighbours to see if someone is in to take the package, they put a card in your door to let you know where it is, whether back at the sorting office or the neighbour..If at the sorting office you can either pick it up yourself or it can be re-delivered on a day to suit you. This should happen in all areas, if there is a complaint it has to be made by the sender at their post office, what happens when that is oversees I don't know. Normally they only hold it for 7 days so they went extra for your parcel. They are usually very good at returning packages to the sender if not delivered. I cannot think of a reason it wasn't delivered. I wonder if the lady is going to her post office for it and not her local postal sorting office which is where it goes back too. May be worth checking with her. pm me if you need any further help, I will do all I can to help resolve this for you.