Login Failed

My website taxitaxi.lk was spam attacked. Lot of user registrations and lot of advertisements appeared.
After that Hosting Company stopped my site and informed me the situation.
They recommended to use captcha.
Because theme number calculating human verification method was failed.
I put a reCAPTCHA plugin but it does not worked.
So I delete google reCAPTCHA – API and Secret key too.
Now I can not log in to admin or other user accounts too.
Finally I went cpanel and restore the last backup of Softcalculations.
But the problem remains.

Now HOW CAN I LOGIN ?