I am having problems with getting anywhere with Customer Services re a missing Voice Service on my account

email sent :

I have given up counting the number of emails sent to Support and Customer Care re my missing voice service
I upgraded my account to 25Gb "lite" service over 3 months ago and until last month - my voice service continued as if nothing had happened.
Then last week - I happened to check my BT on-line account and was surprised to find that I was being billed for calls and on checking my Nildram account - I found that I had "lost" voice
I instantly enquired as to why and it was inferred that this was due to my upgrading my account - which clearly is not the case
My BT bill is now £10 more than normal - so can "Voice" please be reinstated on my account together with a refund of £10 for my BT bill
I have threatened to leave Nildram unless this happens and this is not an idle threat
If my voice is not reinstated by this Friday at 12:00 - You will lose a valuable customer.