Colive — I'm complaining about security deposit refund and putting in wrong charges

I had moved in Colive Brisbane with my roommate back in November, 2019 and left Colive in July, 2020. We had checked out of Colive after talking with the property manager about the security deposit regarding which the manager said that we had to put in the check out notice one month prior or a month rent will be deducted and there was a separation charge extra which was reflected back on the app and It will be credited a month after checking out. While I was waiting for the security deposit to be credited in my bank ac all I received from Colive was two email saying about clearing arrears without any details about the arrears one in the month of August and another one in September. So, I didn't have any knowledge about what the arrear was to talk about to the Colive management where you can't even connect with them in the given helpline number and the security deposit still not credited. I also checked on the Colive app if there was any dues/arrear mentioned but there was nothing on the app. It is only after months today I received an email about the arrears with details and asking me to pay within two days or they will be taking legal action where they have put three different charges which are actually rubbish - 1. They are charging me 2 months electricity bill when I have already checked out of the property and the electricity bill payment was prepaid so there were no dues. So, there's no way they can charge two months electricity bill amounting to Rs. 1600 for just one person.
2. When we first started living in Colive there was many issues with the room allocated which was being occupied by some other tenant and the management didn't even try to allocate the room meant for us and we even raised tickets about the issues with the management and even show every defects to the property manager and after that there was no maintenance of the defects and we were made to stay there with those defects and left the property as it was. So, there should be no repair charges amounting to Rs. 3100
3. Notice Period Charges of Rs. 8000. If there was such charges why they didn't show it in the app when we were checking out. And all of these charges are for just one person. These are being charged with my roommate also with whom I moved in.
And soon after that I received another email from Colive stating that I have to pay the arrears immediately or they will issue a legal notice which will cost Rs. 50000 that they are saying I will have to pay alongwith the arrear amount which is really absurd. And they have put the check-in date as[protected] when I had checked in the month of November, 2019.

Please Kindly look into the issue and help me out with the situation.

Thanks And Regards,
Supriyo Paul