Wrong commitment, wrong documentation, poor customer support

Team - I subscribed for a Xfinity internet and was looking for a mobile connection. Went to the xfinity store. The store executive mentioned that my plan includes a bundle and can have mobile connection as well (Wrong commitment). Before agreeing to take the connection i checked the total monthly bill for internet+mobile and was told that it will be 45 and change. But later received 2 bills - one for internet - $45 and another for $118 for mobile. When approached the Xfinity assitant last week on 26June, after 4:30hrs i was give adjustments on my bill. I refused a additional credit of $15 as well. Later was asked to visit the store. Visited the store on 29th June 2024 and the trainer in the store asked to contact the customer care and helped. The executive on the call promised to update the bill and make it to $23. I have asked them to reduce my plan to $20/month plan which has 1gb internet / month which I agreed. But even after 24 hours the $50 was not credited or the plan was not updated to $20/month. A Reference no was given [Edit: PII]. When i call the support no today i was told that this reference no is dated year 2023 where i never had any connection with Xfinity. (WRONG documentation). Today the call was escalated to the floor supervisor James who had mentioned that there cannot be any credit that can be made. Not sure to whom i can write to get this bill updated and document all my conversations. At different times I have saved the transcripts. If there is a consumer forum in Boston please guide me there. I would like to take this up with the concerned authorities. This team really has wasted a lot of time for me and caused frustration due to communications gaps at different level.