Cosmopolitan plumbing horror

I signed for my house in November 2019 and before I moved in I reported that there was a blumbing issue as shower did not train water and the toilets showed the was a blockage they came and unblocked. We moved in February we had another blocked drain issue, March we had another one it was unblocked and before the end of March 2020 it blocked again and we had to pay to unblock and no one attended to our calls during lock down, the whole of 2020 my drain has blocked every single Month and I had to pay all the time . After lock down our blocked drain issues was logged with Cosmo and they guys said that how our blumbing was installed was nonsense and Cosmo has to dig and re arrange the pipes /fix our plumbing coz with how it was installed it will always block... 3 weeks after that it blocked again and they came to unblock and we were told it was only because new houses are still being built so the drainage is an issue etc.... It's now March 2021 the houses near us are long compled they completed before even 2020 ended but I am here still having the same issue. A lot of people are complaining about a lot of things with these houses from cheap material used to build our houses to this nonsense plumbing. I want Comso to come and fix this as I cannot paying so much and still be so unhappy in my new home I cannot afford to unblock my drain every 2nd week I have 3 little children who are not safe with this drain blocking its a health hazard to my children and this **** pours all over our yard and it stink every ****n month!!