My Landlord gave me my full depost back in April2014 befor I signed new AST with him for next six months. He never put money into govt scheme. Then in September he gave me 21(b). I signed and gave one copy to him and keep one of Sec21(b). He said one copy is for my record. Do you think my notice is valid. Also Landlord is changed last two AST for six months issued by new landlord. Can I argue on these two issues.