Returning Apple Tablet to Xfinity Mobile

I'm hoping someone can help with this as I'm getting pretty frustrated and I'm about one more incident away from getting a lawyer involved. Sorry in advance for the lost post, but this has been an extensive issue.

Starting back in June/July my parents who have been Xfinity customers for over 10 years got to a point where they couldn't afford the cost of the combined cable/internet bill due to price increases and them being on social security income. My mom called and spoke with a representative about ways to lower the cost of the bill. The representative made her believe the only way to lower her bill was by receiving a tablet but said nothing about having to sign up for Mobile. My mom repeatedly told the representative that her and her husband don't use electronics, are on my cell phone plan, and that I'm the only one in the family who uses tablets/computers, and I don't do Apple products. At the representative's insistence my mom agreed to the plan in order to lower the monthly bill. She was told there was a one-time activation fee which she couldn't afford so she asked me to put it on my credit card.

Following month, the price was only down $10, and this Apple tablet comes in the mail. I talked my parents into trying out Sonic internet and streaming since it's much cheaper. We called Xfinity and cancelled our services thinking that would be the end of the situation. Then I got my credit card bill and seen I was being charged a monthly fee for the tablet and my parents received a monthly bill from Xfinity for mobile services (both of which we weren't using). I got on the phone with Xfinity Mobile who thankfully were able to at least cancel the mobile services and refund that charge, but when I asked about returning the tablet that we didn't want I was told they needed to look into it and would get back to me.

Another month goes by, and I don't hear anything from Xfinity. I get on the phone with Xfinity again and I'm told that it is now too late and I can't return the tablet. I get busy with work and other issues so I can't pick up the issue again until after the holidays. I know it is well past the point of the return window and thankfully due to fraudulent activity on my credit card it is now deactivated, and Xfinity can't charge me anymore. However, I'm a responsible individual and I don't want to hold on to a tablet I'm not paying for or using. So, I go into a store, and they won't take the tablet back because it's been too long and give me the number to Xfinity mobile.

Now the third and final issue. I call and talk with them and explain the above. I'm told they will look into it and get back to me in seven days. Well six days later I get an alert on my credit card that Xfinity is trying to charge me over $400 for this tablet that I'm trying to return. I decline that charge. But now I'm back to the situation of how I get Xfinity to take this tablet back and/or stop charging me for something my parents never even wanted in the first place but were conned into getting by a representative giving false statements. If this doesn't get resolved soon my next step will be to get a lawyer involved, especially if they keep trying to charge me for this tablet. Thank you for your help in this matter.