You still have an obstruction in the bowl of the toilet. Have you lost any combs, tooth brushes, hanging deodorant with a wire hanger, plastic caps? Do you have any children that have lost a small toy? The best way is to take the toilet out, take it outside and turn it over (be very careful as the toilets are made of vitreous china) take a small mirror and a flash light and look into the hole and you will find the problem. First before you do all of that, take the toilet out then take a large bucket of water and dump it into the (hole) drain and see if it backs up, if it doesn't back up then take the toilet outside and look into it. let me know the outcome.