Xfinity Home Sensor has not worked for years...

For the many times I have called xfinity home THROUGH THE YEARS to tell them my window sensor WILL NOT acknowledge any new battery, ever, they told me they would ship me a new sensor.  Now, 2 years later, still waiting on that sensor. Having been on the phone for over an hour today for a camera issue TODAY, the agent tells me I am out of warranty for a $20 sensor and I respond, of course it is out of warranty now.  I asked him to look at my initial calls a few years ago and he acknowledged my issue was noted with that same sensor.  Nowhere does it say I declined the service of sending me a sensor back then and there was never a mention of a fee back then.  But now you all want to charge me for it?? I ask WHY since I have been paying for a service that has not fully been functional and when I call, I have to personally spend more that $20 worth of my time to simply connect with a live person to explain the same issue over and over again.  Why isn't there any FOLLOW THROUGH with Xfinity Home customer service representatives.  They did not ever follow through for my issue. The sensor was never sent to me, that is not my fault at all.  I pay a monthly fee so to credit me for a non-functional service only seems fair.  And then send me a sensor that works please!!

I went through the whole conversation with a Supervisor, that is not in the US, of course, and when he did give me the option of getting a tech out here to see what the issue is, I asked if there is a cost, he said if the device is broken in some why I would have to pay--which is understood. I know it is not broken at all since all I do is try to change out the battery but it still will not acknowledge it.  Now, a tech is only available 3-5pm on certain days and can only schedule until 10/24.  I am an only parent to a child and taking care of my 80 year old mother, barely having time to be at this home because I am driving everyone everywhere PLUS working a full time job----I get that time is very limited AND quite VALUABLE, but I see that Xfinity Home Service or Xfinity, as a whole, values only their time and not their customers time. This I find quite frustrating. I am available to be here until 10am for a simple sticker to be removed from a window and be replaced. Nothing is available until 3pm which I can never do because I am in downtown driving in to pick up my daughter from school and do not get home until 5pm, if we do not have after school acitivities. As I said, limited time trying to keep a roof over our heads with a security system which I pay montly that Xfinity is not willing to provide full support for here and replace a simple SENSOR by mailing it to me with no charge after being a customer for over 20+ years, 5 years with this security system.  What is happening and can someone please just send me a sensor for a WINDOW???