I, personally have no doubt that prayers work. Yes, it may not work according to what you asked for. But sometimes God listens to your prayer by giving you what you wanted but sometimes by not giving you what you wanted as that something was not good for you. That is the reason as a Muslim I believe that you should be happy with whatever the result of your prayer is as God knew better than you did. I can give countless examples from other people’s lives but I will give one example from my own life. I always liked Skechers shape up trainers (shoes). Those with MBT or whatever design you call them. We all know they were expensive when they came in the market. I am talking about a couple of years ago, and these ones are still over £50. At that time Barrats had them for about £85, and I usually go towards city centre almost every second day just to wonder around. For over three months I went there, saw, and thought that it was too expensive and came back. One day I went there and they were down to £70. I said to myself almost jokingly that I would wait until they come down to about £30. Then I walked according to my set patron to other shops including TK max and there they had those 100% same trainers for exactly £30. Did I buy there and then? Of course I did as that was the fulfilment of my wish or prayer. I still have those and soon after that day (day or two) TK max did not have them anymore and never ever since then. That is one example of fulfilment of the prayer. Now I would give you another example of prayer not being fulfilled for something better.
Without going into long story, I missed the train in October 1999 that had a crash near Ladbroke Grove. I almost ran after the train on the platform. I was cursing myself as I had to be somewhere very important and was now going to be late. I was late as the train I caught after that was dismissed after a couple of stations due to an “unknown incident” and when I got where I had to get using alternative method, the people there were happy to see me as they knew that I used to take that train there. Was I still cursing myself for missing the train? No one would.