Hi Mergie...
What insurance companies don't know about water damage restoration would fill many volumes. In the first place, whoever you talked to used the wrong word. A germicide is a lay term for an antiseptic. An antiseptic will kill germs in the carpeting - well and good- but that's not what your odor problem is.

What you are smelling is mildew growing on the jute backing of your carpeting. Moisture + warmth + darkness is perfect mildew environment. The mildew will keep growing until you won't be able to even go downstairs the smell will get so bad. The spores are feeding on the organic elements of the backing. Eventually it will get thick enough, where it will surface and form dark blotches on the surface of your carpet, and the carpet is permanently damaged at that point.

IF (and double check on this) your insurance company will pay (minus deductible, of course) for it, then call a respected carpet cleaner in your area THAT HAS AN ONSITE PLANT, not just someone who has a truck setup and cleans only in your home. They will have to come and remove your carpeting from out of the basement, take it to their plant, clean it and apply a FUNGICIDE which will kill the mildew in it, and then professionally reinstall it with new padding.

Your padding cannot be saved. It can't be cleaned, and even if it is dried out it still is filthy from the sewer water.

First, get a written estimate from your pro cleaner detailing everything and fax it to your insurance company. Hound them for an answer, tell them you have a dangerous, disease prone situation in your home. Now we will see how serious they are.

Tell your carpet cleaner to inspect the carpet after it has been cleaned, sanitized and dried. If he sees DELAMINATION in the carpet, the flooding has damaged the carpet and the insurance company must buy you new carpeting. Delamination means that the primary is separating from the secondary in the carpet structure; in other words, the nap with the latex binder and webbing is pulling away from the jute backing. If you grab the top nap with one hand and the bottom backing with your otherand pull your hands apart, the top will flop away from the bottom.

While the carpet is out, mop your foor with 1/3 bleach and 2/3 water to disinfect it and let it dry.

If they will not cover you, post back and I will tell you what to do.