Vodafone ruining credit file

I'm in despair nobody at Vodafone will help me and one even asked me to take me for a drink next time I'm on holiday in Egypt.... I wish I was making this up. I'll try keep this short but if anyone can help in any way I would appreciate it.
January 2015 I decided to leave Vodafone and move to EE with my current number. I called customer services on 15/1/15 (A date given to me recently by a member of Vodafone staff in an in store branch when looking at my account history) During the call on 15/1/15 I was tolls my balance was £0.00 no pending bills or payments due all up to date so "feel free to cancel your direct debit" I had just returned from Egypt and the customer service advisor (in Egypt) told me he would love to take me to some "chic bars" next time I visit the country. I politely declined and verbal re confirmed it was OK for me to request to transfer my number over to EE and leave Vodafone and cancel direct debit. (I had been a customer from 2012-2015 and never missed a payment) He confirmed so I did as I was told. 9 months pass and I apply for a bank account and I was declined.. How? Check Experian credit score and I have delinquent payments of £23 from Vodafone against my account from Jan-September 2015

Vodafone said there is nothing they can do as they sent me alter (funny how I never received that letter when I easily received the others every month for over 2 years) and as such they had no fault and couldn't removed the red marks agains my account but as a "GESTURE OF GOOD WILL" they will wipe the £23 and email me to confirm the account is actually closed. This was from two members of staff in their CEO complaint department on 14/9/15 .. No email ever came and now in October guess what .. another red mark against my name for the same £23 4/10/15..

Now when I call Vodafone they can't find any record of me anywhere even on their "old system"


Every time I call them it costs me. I'm 24 years old recently returned to University to study in the medical field, and I'm unable to apply for any credit/loans/student bank accounts because of this. If they refuse to accept any responsibility at least they can stop when they said they would.

Does anyone know what to do. I spoke with someone again today from the mobile phone customer service team.. they almost giggled when they said they couldn't find any record of me like it was comical.. and said to call the credit team during 9-5pm and then they said their connection was poor and the line cut out.

I study, work, and have no disposable income. I do not know how or what to do to rectify this and just stop them ruining my credit score. I never received any letters regarding a missed payment or payment still pending after 1/1/15 .

Desperate for a solution