Bad service after being a costumer for 20 years

Hi started the journey a few month ago when I tried to DOWNGRADE, to a lesser package deal as I do not need an open phone any more. I was told I cannot but have to wait till my contract runs out completely. That happened in en Feb this year. I phoned cancellations and was met by a well spoken lade, convincing me to stay but downgrade only, what we did (SR***). I specifically asked for 800 minutes as that is what I still uses per month. My wife sell number the same but in her case only 250 minutes. Some other stuff was discussed and a promise of a payback of around 1 year of subs paid to much was discussed and I was give confirmation that a payback was possible (SR ***) same number. I ran out of minutes on the 12 Feb. flabbergasted what happened now I phoned and was greeted by a not so friendly voice telling me I will have to wait for the investigation to be complete before any thing can happen. I am sitting without the ability to phone for a week or so !! I just want to run this contact out and go somewhere else. That is after more than 20 years a costumer and for years on the RED PACKAGE.