You should just wait a bit more. Usually postal delivery doesn't operate on the weekends (varies between countries) and you can check your local postage service for the delivery days. I know what it feels like when your item doesn't arrive at expected time but don't panic, it's very normal, especially if it's international delivery.
An item worth 15 euro isn't prestige enough for a tracking number. On average, only item with a value of 50 US dollar or higher should come with a tracking number. It is not a law, but it's more of an ethical issue and MOST ebay seller understand this.
I do not advise clamming 'item not sent' or negative/neutral feedback if the item is late by a minor time because postage is an external function which is out of their control. Many buyers do not understand this or rather, forget about this important factor. With online shopping, it's always advice to approach any matter positively.
However I don't like how he/she 'blank you' (I don't know what that means but it gives a negative connotation) and you can comment that on your feedback if you feel offended. In conclusion, if you don't receive the item within the next week, and poor communication from the seller, then ask for a refund. You can use your negative feedback as a bargain chip since small ebay sellers can't afford to receive negative feedback, especially if it was 'because I didn't receive the item and he not giving me refund willingly'.
If he refuse, then clam the item as not received and get your money back forcefully, then give him negative feedback. It might sounds evil, but it's not because you gave him chances to redeem him/herself and he/she didn't take it, so it's your rights to warn other consumers. Hoped it helped.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.