Sickening Collections department badgering me daily

I am seriously being tormented by the collections department. I received 5 emails in a space of 15 minutes all referring to one account which by the way i am paying through a collections agency they have sent to also harass me which they seem to have NO communication with because now i am being plagued by Europcar and a collection agency. This is really unacceptable and totally unprofessional and totally bordering on hounding a person. If this does not stop i will escalate this matter to the ombudsman. I have had enough!!!!!!!!