Personally I'd send them a cease and desist letter and say unless the next thing I receive from you is a properly constructed letter before action outlining exactly what you say the legal claim against me is, then I will consider the matter to be closed and won't be conducting litigation by correspondence any further with you about this specific matter.
Personally I'd send them a cease and desist letter and say unless the next thing I receive from you is a properly constructed letter before action outlining exactly what you say the legal claim against me is, then I will consider the matter to be closed and won't be conducting litigation by correspondence any further with you about this specific matter.
(IIAL BUT IANYL)