Damaged drainage pipes-No aftercare service

In 2022, I contracted Easy Grass through their agent Walter, who is also the team leader to take off a patch of grass at my house, install the artificial grass and also put some tiles around. I should say the work was good to my satisfaction. Their work had a 10-year guarantee. In a year the grass started to pull off at some areas and i contacted Walter who promised to come, however he never did. I contacted him months later and he told me that he does not have transport to come to my area. In 2023, I noticed that my drainage for water coming from the gutters was moving slowly and I will used drainage equipment to unblock and it worked. Now in 2024, I noticed that I will have constant blockage on the pipes from the water coming from the rain which is the area around the grass installed by the company. I should indicate that I did not have the problem before the artificial grass was installed by Easycare Grass. I informed my insurer about the blockage, and they sent a plumber to assess and repair the blockage. The plumber came to assess and discovered that the pipes underneath the grass were damaged when they used the metal rod to try and unblock the water. I have informed Walter who was the team leader through WhatsApp messages, and he has since ignored my messages. I have also emailed the offices of Easycare Grass with no success, they have never responded to my email. I would like to request that hellopeter assist me in this regard for the company to take responsibility of the damage they have caused on my drainage pipes.