Best, On 7 December 2018 I ordered a Xiaomi pm 2.5 detector (product number: NF2018120709484989900), I paid € 55.16 for the product and for the fast transport 30.71 euro. The agreement was that my product would be delivered 5-7 working days. On December 19, 2018 I contacted the seller of NewFrog and I asked why my product was not delivered, on December 20, 2018 they said that the product is not in stock! But they have said that they would send the product again within 5-7 days! I am not content, this takes too long. I needed this product for my studies, I am now running into problems because of his mistake, I told him that I agree with his proposal, but he will return the money from the fast transport (30.71 euros). The second possibility was that he would refund all the money (85.87 euro) in my account and pay 25 euro compensation for the time that I had to wait for nothing and that he kept my money for a few weeks. I have also written to him that if he wants to do business he must also take on responsibilities. If necessary, I can send our conversations via email to you. You can contact me here: [protected]@hotmail.com Thanks in advance. With best regards, Hoxha