Direct Debit problems for 6 months

I set up a DD for my partner's bill last October have just last month entered chat conversation asking why after 6 months they still aren't taking payment by DD and cutting the phone off every month even sent a image of both mine and my partners DD set up on with our bank all the lady I was speaking to kept saying was I can see you've sent me proof but we don't have it this end this has been 6 months they even sent me a email confirming the DD had been set up not long after stating a DD had been set up with the usual if it was you ok if not contact them /bank I obviously didn't make contact as I had done it so I'm quiet frustrated with it now I set everything DD as i struggle with remembering things due to mental health and having ADHD and being on the spectrum alongside several other mental health conditions which I didn't really feel comfortable putting on this post due to bad experiences with acceptance of this , I genuinely can't for the life of me understand how it's a fault on my part as it's not the bank refusing or stopping it I've gone back and checked and there's no attempt to take the payment it's a joint account so has both names on it and has been active since October anyone able to give me any advice thanks Tia