Been using this company for a long time. This number is for NCH/Certified labs/Chemsearch/Mantek (All sister companies). If you tell the reps to stop calling, in a polite manner they will stop calling, it's actually a rule of theirs. You can't just pick up the phone, scream "stop calling" once then expect them to understand why. Their purpose is to understand what happened out in the field, and fix it if it was wrong. They can't do anything with your account without a reasonable excuse but, if you give them one, they'll delete your account and leave you alone. They don't want to waste their time either.

Just a tid bit of advice, the nicer you are, the nicer they are and they're just trying to eat like the rest of us.