Doing what you promised

I traded in a Samsung S-10 on a Samsung A-15 which was incompatible with my hearing aids. I returned the A-15 and purchased a Samsung S-24 and was told at that time, the S-10 trade in would reduce my monthly payment on the S-24 by $10 per month over 24 monthly payments ($240). Instead I got a check for $35. Since receiving the first email, saying I would only receive $35,  I've called customer service 3 times. This took 24 days, because the first 2 times I was told the problem was resolved. Called again once I discovered it wasn't resolved. On the third call I was told all they they were going to give me was either, the $35 check or $35 deducted monthly over 24 months. Apparently she was the first honest agent I spoke with. Too bad the only honesty I encountered was after the deal was irreversible, see, I was also told it's to late to return my phone and cancel the purchase.

Basically, bend over and smile because there's nothing I can do about it.

I'm retired, on SS, and money matters. I feel like I got mugged for $205, and can't believe Xfinity is desperate enough, or greedy enough, to be in the business of mugging old men for peanuts.