Debt collector Revco very unprofessional

Numerous communications to this company with regards to my account keeps going on deaf ears I have what's app messaged them as well as emailed them with regards to correspondence which indicates that they should not contact me directly and speak directly to the company acting on my behalf but to date they continue sms's phone calls its like they don't seem to understand or read the relevant documents that was sent to them via email and what's app message as they requested feedback via these methods on a sms. Please stop makes the company seem like they can't comprehend a legal letter And is it extremely unprofessional I hope other companies never use revco services as it is very unprofessional. No feedback in writing from my email or what's app message.