No response, just pure silence from FNB

I logged a ***** claim against my cheque card on 19/03/19. My claim was reviewed and I received an SMS a day later on 20/03/19 to advise that my Debit Card claim has been finalized and that a letter has emailed. I checked my email (which is my primary communication preference with them) but there was nothing. I emailed them back to inform them that I have not received the letter, but had no response. I emailed them again and tried calling them today on ********** but to no avail. I was on hold for about 18 minutes and only got a "experiencing high call volumes" message. All I need is feedback for my claim or the said letter to be emailed. Is that too much to ask???