Disappointing service - Group Schemes

I am writing to express my disappointment and dissatisfaction with old mutual group schemes. I changed jobs in 2023 and my salary date also changed. I called OM to ask for the debit dates to be changed, for my retirement plan it was swift and they changed it over the phone. I was then transferred to GS where there was no answer. I kept calling and calling and never got any assistance. This is after a two year query just to sort out my last name which was suddenly changed. Eventually I called some other number on 23rd May 2024 and was assisted by a Nichole who couldn’t make the changes herself but sent an email on my behalf to GS enquirers. Only on the 27th of May they asked for my ID copy which I sent to them and STILL NO CHANGES MADE. I’ve sent numerous emails regarding this and Still tried to call and wasted my time as I still get no response.