PHONE LINES NOT WORING - 2 WEEKS TO GET A LETTER

Ill leave a 5* review if I can get this sorted. Been trying to get a closure letter for 2 weeks. The relevant department does not answer after hours spent on the phone holding. I have filed a complaint in the online banking but it keeps writing from a generic email address that tells me they will get back in in 2-5 days(its been 2 weeks). Really. is there any way I can speak to a human who can help me as these computer generated mails are not helping and the phone lines are not working. Really frustrating.