Internet Bill Increased for No Reason

I got my internet connection and two unlimited mobile lines in Oct 2024. So I get a mobile discount of $45 every month in my internet bill (Bundle offer). But my mobile discount got reduced to $15 from March 2024. I tried contacting the customer service. I was promised with a callback in 2 hours (before a few days). But still I didn't get any updates reg. the same.

I tried calling again to get an update. Now Mobile dept is telling that its not their responsibility and Internet team is telling the same. They are just connecting me to both the depts back and forth on the call. No response is provided. It is so irresponsible. If both depts are separate, why Xfinity is even selling a bundle offer. Please resolve this issue ASAP. Thanks! 

Can someone help me on this?