Maybe they detected,that the ddos attack coming through your site.they done the same with me.,it was so disappointing for me...(my site never received any ddos attack)
Ask for your site backup and transfer your site to another hosting company.This is the best solution.Im sure that the ddos have nothing to do with the hosted sites,it is related directly to shineservers.
Since my site got transfered to another hosting company,my site is always online without any problem...
P.S.
Shineservers have a very good and honest support,so you can solve your problem for sure.