being sent from pillar to post

I received a letter stating that a refund was due to me, i must forward certain docs, I did this on the 24 Feb 2015, only to get a response to say i sent incomplete docs, on the 25 I then called again and informed them that all the docs i sent are correct, the lady apologized and said this was a mistake on their side. On the 27 I then received another email saying i must confirm my bank details, but on the docs sent on the 24 i had attached a 3 months bank statement. Needless to say, i filled in yet other forms and sent them. Since then I have not heard nothing from them. I then decided to call them on the 10 March, I spoke to two gentlemen who each made me hold for more than 10 minutes to get feedback from Finance. No one called nor emailed me with the income. I then called in again today (11/03/2015) and was assisted by a lady who said comments were captured on the system that the credit controller is not sure why i have not been paid yet. and that there is nothing she can do but escalate my query YET AGAIN.I requested to speak to someone who is in the finance dept and was told that's not possible, when I insisted I was then transferred to a line that was just ringing.