microworkers is a scam site

as my exam was going on I I had not used there site from last three month but when I logged in few days back and completed 3-4 works then I logged out.but when again I logged in 30 minutes later I saw that I cannot do any job.so I mailed them but they only replied me once and asked me for my user id when I replied back theere is no response from them.I sent them two more mail but now its 30 days passed but I didn't got any single response from them.