Discovery Heath abysmal service

These people refuse to resolve this. I have paid them the full amount due to the cent, as per their settlement letter to me. Their collection agents ITCBA constantly harass me for some amount owing to them for collection fees but discovery contracted them, NOT me. I have paid the amount due to discovery, and these people constant harass me. Every day and Discovery Health refuse to do a thing to resolve this. I’m sick of it.