I have finished paying off my account with RL Daly Anttorneys they are refusing to give me my paid up Letter

I have finished paying off my account with RL Daly Anttorneys they are refusing to give me my paid up Letter. They are telling me it is going to take 4 months for the letter to come, this is really affecting me and financially infringing my credit profile. I would like to recieve my letter to log a dispute with ITC as this has been a problem to me. This is bad service and unprofessional.