Why is my ex boyfriend being so rude to me?

this been going on for a year now. me and my ex boyfriend was together for two year. my ex boyfriend left me for someone else. but was lying to me about and was treating me like an back burner. so I was being the bigger person told him I knew the truth cause I saw them together. he was playing bad head games with me. saying he was never coming back. but came back two times. so I was just treating him like a friend now. I don't go after guys who has gf`s. its not right.. so know he got mad at me and won't talk to me now. but is his friends who lives next door bring up the past with out saying his name and then I say his name. then they smile about it. they do this 2 weeks before I pay lot rent to my ex boyfriend friend grandpa. so I text my ex boyfriend since its been awhile and maybe his over being mad. I texted him, he waits the next day to ask me who is this and calm he don't know me. but I called and its still his number. why he being so rude for? cause I only want to be friends?