Bad service

I lodged a complaint before with one2one till today it has not being dealt with fully. The last time I communicated with one2one agent they promised me that they were going to reverse the payment I did in June 2015 and July 2015. They promised that the refund will be in my August 2015 statement and when I called in August the lady who was very rude to me told me that there is nothing she can do if the amount was not credited back to my account. Apparently the accounts department didn't do their job. She said I must check my September 2015 statement. The September statement has closed no refund was done into my account. one thing I know is that I will take up the further if it is not resolved before end of September 2015