Please forgive the long post but there is a long story to the idiocy and incompetence at work here.

This started last year when i had an offer with my statement of 1 year 0% interest on purchases before a certain date.
I decided to take this offer and purchased a few items so i could buy the items and leave the money in my bank account earning interest at the same time.
All was fine until around February when i purchased some festival tickets on my card. I paid off that amount straight away. The festival was cancelled and i received a refund to my card so i sent a message via the online banking site asking if i could have that amount refunded to my bank account and when doing so would that return my outstanding balance to it's 0% promotional rate, to which i received a replay stating it would be.

In a future statement i then notice i have been charged interest, so in reply to the message i received stating my account would be returned to the promotional rate so that information and confirmation was attached to the message i pointed out to them i should not be being charged interest.
I received a replay back from someone who obviously didn't read the message history i had attached saying my promotional balance had run out during that transaction. So i rang them up...

After around 20 minutes of attempting to fob me off the guy on the end of the phone eventually relented and said he would have a look into the issue and after a few minutes saw what was going on, admitted it was rubbish design of their system that caused the issue and refunded me the erronus interest as well as resetting my balance back to the promotional rate.

All was fine until i used my card again. Same deal, purchased something, paid it off straight away and to top it off and make sure there was not a repeat of the last problem i even sent them a message with the history of what had happened before, stating that the money i was paying was to go against the purchase i had just made and that my remaining balance would be at the 0% promotional rate (As it should according to their terms and conditions anyway) and could they please assure everything went smoothly.

I received a reply stating that was all fine...Guess what??? It wasn't! The same had happened again.

This time s skipped the internet banking message and went straight to the phone. Again after a lengthy discussion with the guy on the end of the phone trying to show me how i was wrong and me throwing facts back in his face. When he ran out of any semblance of plausibility he eventually relented and took a closer look. Surprise surprise, again he accepted i was right and said it would be sorted.

Obviously it wasn't put right as the next month my promotional rate was ending so i paid off the remainder of my balance only to find out i was charged more interest on 0% promotional rate balance which i had paid off!?

Another phone call ensues, you know what happens next i get a refund etc but i also demand to speak to a manager about the total incompetence of the whole scenario. I am told all managers are in a meeting and someone will ring me back when it is finished.
No one rung me back but i did see a interest adjustment on my online bill and my outstanding bill was zero so i decided to leave it there.
It doesn't end there folks....

This month i check my bank account to find out they have taken money from my bank account to the value of that interest charge, so i check my online statement to find that interest adjustment has gone and instead they took money from my bank account then provided me a refund back to my credit card so another phone call has ensued and i am now waiting for a manager again as they are all in a meeting.