Liberty Life Incompetance

I have had a rtirement annuity with Liberty Life for over twenty years now. The premium is on a stop order so it comes directly off my salary before I even get my salary. The premium is paid religiously evey month and in all these years, I have never skipped an payment. However, on four different occasions now I have received threatening emails from Liberty Life, informing me that one or more premiums were outstanding and if not paid immediately my policy benefits will will altered or made paid up. I've responded on all occassions and provided proof that their information was incorrect. I hardly even get an apology. the staff are completely incompetant and not very friendly. I am so appauled at the service Ive been getting especially since I am a long standing loyal client.