im concerned bar a few old posts ive merged here from your old dmp plan thread
that you let this get sold on without a new cca request
assuming the agreement is enforceable
and have blindly been paying a dca?
send them a new cca request.
Troublesome tenant complaining repeatedly without cause and not paying the agreed rent - sounds like it's time to tell the agents to give the tenants notice to quit.
In my experience over years, some agents are more interested in getting any tenants, rather than getting you "good" tenants - they just want the commission, regardless of what happens to your property or (lack of) rental income.