yes you write here you used Nokia 302 two days ago (correct it with last day when you used yappari actually) and then gave phone to wife/brother/sister, and then got Samsung Galaxy S6 (replace with your phone model you using), and when tried to register, you see blocked (replace with actual text you see). And better do not tell anything anymore like "i never used unofficial apps" or so. Just write them something like: "i do not understand why it stopped working, please help me. i paid for whatsapp at (write here date when you paid for whatsapp) / or ask them maybe you free whatsapp time is ended and you need to pay and ask how to do it". It's better social engineering tricks you can do in this situation