Bad experience with Microsoft, I cancelled my Microsoft Office in May and am still waiting for my refund

Bad experience with Microsoft, I cancelled my Microsoft Office in May and am still waiting for my refund. Its going on five months and the only feedback I receive is that the matter has been escalated or being investigated. I was requested to forward my bank details in order for a bank transfer, email received it was processed but my Bank has confirmed that no monies are due in my account going back to May. Every week I receive the same email and am at my wits end.