We've been getting harassing phone calls consisting of nothing but annoying tones from this number, as well as other "unknown caller" numbers. The calls started right after we hit a rough patch and got behind in payments to American Express. We suspected it was AmEx, but didn't know for sure, UNTIL they slipped up and used THREE of those same phone numbers to instead deliver an automated message ASKING US TO CALL AMERICAN EXPRESS. (It's a good thing we logged those numbers!)
In our case, almost all the calls are pure harassment, consisting of loud "beeeep beeeep beeeep" tones that go on and on. When the answering machine answers the phone, the tones continue until the machine times-out and disconnects. When we answer the phone, we are also greeted by the same loud tones. These are not telephone company type tones; at least, not like any I've ever heard before.
Generally, we get about 2 to 4 (or more) of these "tone" calls per day, coming in from any of the following numbers:
212-300-5091 ...tones
212-365-4761 ...tones, or an automated msg from AmEx
212-380-3114 ...tones
602-537-9011 ...tones
623-492-7299 ...tones
623-492-8037 ...tones
623-492-8976 ...tones
800-266-5832 ...tones
800-266-7073 ...tones, or an automated msg from AmEx
801-945-9060 ...tones
801-945-9061 ...tones, or an automated msg from AmEx
801-945-9065 ...tones
866-260-2386 ...tones
866-544-8416 ...tones
866-884-0976 ...tones
954-503-1806 ...tones
954-503-2843 ...tones
A few calls from these numbers were "silent"...no tones, no nothing.
A few calls of the loud tones have come in from blocked IDs (unknown numbers).
Anyway, embarrassing as circumstances are, I figure someone else might find this info helpful.