From the Aston Villa website

Aston Villa can confirm that, along with a number of other high profile football clubs, the Club is temporarily unable to accept any applicants for credit on Early Bird Season Tickets.

The credit supplier, Zebra Finance, has had its funding ceased and the Club are currently exploring alternative credit solutions for season ticket purchases.

Supporters who have already taken up the finance option through Zebra are unaffected and fans can still continue to purchase Early Bird Season Tickets without a finance plan.

Seems pretty black and white to me.