Giving interest money to buy raffle tickets

I had around $48.5 of interest money in my Australian bank account. I wanted to get rid of it by giving it to a poor person. A few days back, in my office, there was a collection for a bushfire relief fund and it required staff to buy some raffle tickets which the company was giving a gift to the winner. I thought of giving that interest money as a donation so I told them that I am happy to contribute $50 but won’t take any raffle tickets. They requested a lot so I took the raffle ticket but Alhamdulillah I didn’t win any prize.

Now my question is, was my niyat of getting rid of the interest money fulfilled or not? Do I still need to give that $48.5 to a poor person or will the amount of $50 which I gave in charity suffice?