Finchoice is ruining my life

I can not believe how unprofessional Finchoice staff has been, first in January I double paid my two accounts Mobi and Flexi I then called them to refund me, they gave me run around and as they have always done they topped up my flexi loan and I borrowed the top up because my other bills needed to be paid and was waiting for my refund. When I was not refunded I reversed both payments and got only one. When I followed up on the second refund they said I won’t get it because of the top up and I’m thinking to myself how am I paying for my own money which was paid to them by accident?? I left it because had no energy to fight with them. I finished paying for the mobi account and I’m left with the Flexi and when I checked my credit score it was insanely low and I saw finchoice showing Two months in arrears and was shocked because I have never missed a payment and when I called phone got dropped 3 times and I gave my phone number so they can call me if the phone got cut but they never did, so I sent them an email and it came back saying I owe them money for two months. When they owe me money I double paid and they gave it to me as a top up loan and I am paying for it every month now they say I owe them 2 months and even put that on my credit score which has only started picking up from the damages they did in2023 which I fought for months and still left damages on my credit report. Can someone please do something about this company it is getting ridiculous ombudsman or someone needs to intervene and investigate.