bad service

I guess old mutual does not take their clients seriously regardless of the consequences. I have been in and out of old mutual walk in centers asking them to change my debit date from 15th of every month to the 25th of every month from last year (2019) December, however I get debit on the 20th of every month and they have been calling me to say that I am behind with my payments. this has had a negative impact even on my transunion report. this was raised with old mutual number of times and still there has been no change. I am not sure who to speak to anymore because none seem to be willing to assist me. I am very disappointed with such a poor service from old mutual. even this month (November 2020) I was debited on the 20th and this is very frustrating considering the fact that even with transunion it shows that my old mutual account is behind. I would like to get a representative from old mutual who will resolve this asap including the record with transunion!!!!