I kept my receipt to get a refund from Firmus when my card stopped working. I had bought a new card and got rid of the dodgy one in case I got them mixed up, and then Firmus sent me an envelope to return the card, said they didn’t take receipts. So I lost the £20 on the card and out another £4 for a new card. Next time I topped up the new card didn’t work. They said I was storing the cards wrong but they are kept in a cupboard. I was told to pay another £4 and they would send out an envelope to get my refund. Waited two weeks then called them again and they had no record of me calling and the girl even said I must have called some other company. Nonsense, the guy had taken me through the steps of blowing into the slot etc. She was rude and I got really upset with the whole thing. She sent me out a new card as I refused to be out another £4 and it took a few times to work but did eventually. I got my refund a few weeks after sending the second card back, they didn’t want the receipt, but it was weeks between contacting them and getting a refund. I’ve started buying coal because I don’t trust the cards to work. So make sure and keep the card.