as per my knowledge of the classifieds rules, it is clearly stated as follows

#3.- QL does not expect to see repeat adverts posted within 24 hours of the original advert appearing on the site...

Just go and check the classifieds rules again

http://www.qatarliving.com/guidelines/classifieds

If you still have problems posting, then the best choice is to contact the Mods/Admins of the site for clarification or help.

http://www.qatarliving.com/contact

Regards!!