No birthday voucher received

On or around the 20th of February I called the Dion call centre to advise them that I had not received my birthday voucher as promised on my statement. The call centre agent told me that she would forward my request to the \vouchers department"where they would get someone to email me the birthday voucher. I waited about 2 weeks and still didnt receive anything. I called in again and another agent said that the lady who deals with the birthday vouchers was not in yet. She would be in at 10:30 and she would give me a call to arrange that i receive my voucher. I didn't receive the call back as promised. On the 10th of March I received my birthday voucher in the post. It had already expired on the 28th of February"