Hi,I need to know why my credit application is rejected without any reasons?

I have been rejected a credit card recently because bank closed my credit card which i got 15 days back because i finished my study and mistakenly applied a student credit card.I paid all my due amount.Then i applied to another bank and they rejected my application without any reasons?Now i want to ask if i can get a credit card from another bank or should i wait before applying?Can anyone tell for how long should i wait to apply for another credit card once you close your current card although i got that recently given i have no bad debts.Thanks :)