Financing a laptop as an apprentice with 600 euro net earnings at saturn?

Hi I'm 18 years old and now earn 600 euro net in the second year. I wanted to buy a reasonably priced notebook worth 350 euro at saturn, but it was not possible and was rejected by the targo bank. As far as I know I'm not negative in schufa. I also have a mobile phone contract and a dsl contract if that has an impact on it?

Borrow the money in the relatives, friends or acquaintances and pay it interest-free monthly in small installments.