They are continually marking their territory because you have not gotten rid of the smell of their urine. Wherever they go, you need to clean immediately and sanitize. Once you get rid of the smell it should help them resist the urge to do it again. Make sure they are going out 3-5 times a day and do not leave them unattended in the house. If you must leave but do not want them outside, start putting them in one room, like the bathroom or laundry room.
But above all, sanitize every spot they have ever urinated in.
