iPod touch declining my debit card?? why??

My dad gave me his old ipod touch and I keep trying to create an Apple ID but every time I do, it asks me for a payment method. I press VISA, then enter my details but it keeps saying my debit card is declined. I have no other cards. I read somewhere that you can pay with PayPal? I've no idea why my card keeps getting declined.. I only want to download FREE apps anyway! The only options I have as a payment methods are VISA, Mastercard, Amex and Maestro or an iTunes gift certificate/gift cards.. I can't even download free apps because it still asks for a payment method!!