I would advise you to get a professional carpet cleaner to take a look. Using any type of bleach on a carpet could cause you more problems, the bleach could effect the backing, causing it to pull away from the pile(delamination) and never believe what the shop says. Take it from me, I attend some of these people who have bought stain protection as part of their purchase, they get told all sorts of lies so that they will buy it and earn commission for the salesman, like "our stain guard contains teflon, you could drop an egg on this sofa and it would slide right off!.; "this carpet will be stain proof but if a stain does occur then we have specialist cleaners" a contradiction in itself.
You mention hiring a cleaner, again I have done this when mine was out of action, no heater, a crap wand and full of all sorts of unmentionable's and I recently attended a woman's house who had hired a certain doctor for her carpet, thing was she ended up with three different doctors not working properly the final one dropped it's lot all over her cream carpet, leaving a brown stain. I was given the job to clean it up using my HWE. The cost of her hiring and doing it herself was more than what I would have charged to do it for her.
If in doubt, do nowt, call a pro out.