Total lack of response from Discovery Insure

On 3 August I canceled my policy with Discovery Insure after experiencing problems for over 2 yrs with Vitality Fuel Cash back. After numerous calls and e mails the answer was always "its been escalated " Yet again a month had passed and I've not received the outstanding amounts for Vitality cash back. I find this lack of sorting out problems very shoddy not to mention extremely unprofessional and am now wondering who else is able to resolve this issue. Do I approach the Ombudsman?