Lufthansa — Refund refusal

I was advised by Lufthansa that because of covid my flight for September had been changed resulting in me not being able to take this revised flight. I received an email and clicked on the option 'i want a refund' then I heard absolutely nothing. This was on the 9th June. I then contacted them and was advised my refund had been lifted and to check my bank. Nothing. Then I was told to contact my bank which I did. Nothing. I contacted them again and was told twice the same thing. Yesterday on the 12th July I was then informed my refund had been sent in the form of a voucher. I advised I have never received an email with a voucher. I was told to check my spam which I have already done. After informing them I was told that they can not resend the email again as it is automated. (I have to have this email to click on a link to convert from a voucher to a refund) now because I have not been sent this email they are refusing to do anything for me and the customer services adviser has confirmed this to me. I am utterly disgraced and desperate for help.