Can't get rid of mold for some reason.?

I sprayed a basement, concrete wall with bleach solution to get rid of mold. It worked then, which was about 4 weeks ago. The mold is starting to resurface through a waterproofing product called drylock. It is suppose to prevent mold and mildew and waterproof the wall. In the corner of the wall the mold is coming back and the waterproofing stuff is different shades. I presume it is moisture trapped within the wall causing the color difference. Any suggestions on how to fully eliminate the mold. For the water issue, I can't afford to have extensive waterproofing work done. The issue is not as bad now but I don't feel the work I did was successful enough for the long run. Any ideas?