Momentum Investo bad service

I do not know why they even bother having online self service if the requests we put through are not adhered to....I have a retirement annuity for more than 10 years now and have never missed a single payment and nearly did this month because my request to move a debit order to the last day of the month was not done , when I call their call centre I get moved from pillar to post ......I am very disappointed and mind you I have other organisations offering me offers that will allow me to move with my benefits etc