Why have customer service when you don't assist your customers

So I am renting a decoder from onair for a while now, about a month ago I started having problems with the decoder but thought nothing of it because sometimes the signal is bad or maybe the remote needs new batteries. then one evening our power went out and so the decoder had to reboot, the glitching became worse, I followed the instructions on how to do a proper reboot, changed the batteries but yet it still freezes and the recording function gives problems, I called onair but their line is always busy, I whatsapped them but later realized the portal was last accessed 30 Nov 2020 so I resorted to emailing them, it's been a week with no response just like I got no response when trying to change my banking details eventually I got threatening smses saying that further action would be taken against me if I did not make the payment asap (the payment was late only due to them taking forever to assist me in changing my bank details) I sent them an email asking for their banking details and a reference so I could make the payment but received no response, a few days later I was called to inform me I still owe them the money, I informed the consultant that I had emailed to request their banking details but they had not yet rep**** and she said she would sms the details to me. My payments are now up to date and as far as I am aware since it does not yet belong to me it's their responsibility to fix or replace it but they're ignoring me. their customer service is terrible, looks like they don't give a **** about their clients only the money they get from them. I m hoping this review forces them to respond and assist me because I don't know what to do anymore. I am tired of paying for a service that is almost impossible to use