Detroit Water and Sewerage Department complaint: Non main sewer clean out is damaging my property

I have had this house for 29 years and the Detroit water and sewage has never cleaned the main sewar line leading away from my home. I have had numerous basement floodings from them never cleaning the line. I have been told its a private line when it is not, I have several neighbors whose basements are flooding also. I have a corner home with a sewer in front, my left side and in the back and the blocks water runs down to my house. My basement is flooded 21721 and it took them til 3621 to come to my home with no resolution. I called again, service 36485 for them to clean the main sewer line and have been lied to daily that some will be coming out and I am still waing. The main line is in the home behind me yard and I was told by the water company that its my responsibility because its a private line but its on someone else’s property which makes no sense. I have no rights to dig up their back yard. I am a grandmother snd disabled and have no money to keep paying for a problem that is not mine because the water company has not upgraded pipes since the 1800’s but raised the bill for rain water and they are not even keeping the sewer water out of my home that has truly damaged my cedar wall panel along with the foundation cracking from the water company neglect. Here are dates and service’s since 2019. I am getting sick from the smell and this is a covid era, i also have grandchildren with bronchitis and asthma who have to breath this poisoning in. This matter is not being taking seriously from the water company while I am continually suffering, please respond with a resolution.

42019. 690
42619. 955
71619. 5115
81919. 6407
32020. 15105
33020. 15117
21721. 34104
31521. 36485