DNAtel not providing speeds as contracted

My (and the rest of the residents in our Estate) line speed drops almost monthly, sometimes more, to below 10% (less than 5Mbps on a 50Mbps line). My ISP is Axxess, which always blame DNAtel. It has now been 4 days since the issue has been reported and no feedback other than "we are working on it". There is no attempt from either Axxess nor DNAtel to compensate customers for the lack of service nor resolving the issues once and for all. My recommendation to any Estate or Complex planning to use DNAtel is DONT