Anyone else sent a letter to to CMW as suggested ?

bit of advice please.....been following this forum for a while as received my 1st letter from ACS in July. Sent the LOD to that and also the 2nd letter.....however, this morning recevied a 3rd letter saysingthat they dont recognise the LOD as a template, etc and have withdrawn their offer for me to settle claim by paying £295. What I dont get is they've enclosed another offer saying I can settle for £255 or be taken to court if not paid within 21 days.....so they withdraw the offer and then give me an offer to settle for less ? Anyone else had this ? needless to say will not pay as totally innocent of the charge