Help my wordpress site has been hacked

Please can someone help, my wordpress site was hacked over the weekend.

I use xilo to host my wordpress sites. It was hacked over the weekend (I believe through a tim.thumb script that my main theme was using). I have three wordpress installations on my server. The main one was hacked by a malicious script that basically deleted all my files. I have backups of the files and the databases but silly me, I had let it lapse for a couple of weeks before the attack.

I contacted my host and asked them to do a system restore from a couple of days previous to the attack. They didn’t respond straight away so I decided to sort it out myself I changed all passwords and uploaded my backups both databases and files. Whilst this was happening the whole account, files, access logs and all was deleted.

They responded today and have said that they have restored from the date I requested but there are lots of files missing that I know were there on this date. I am no developer and I am a bit confused as to what to do now. I have placed the websites behind a 503 which just allows me access. But I cannot find the wp-admin.php at all, it returns a 404 error page. Can anyone give me any pointers on what to do or ask for from my hosts?

Many thanks