About phone monthly payments

[sanfer]

I bought 2 phones from Xfinity in 2018, LG K30 and LG Stylo4. Love them both. I had not entered the web page in a long time. Today I did and noticed that both phone prices have gone down. Example: for the K30  I am paying 7.50$ and it went down to 4.99$ per month. The other phone has not changed. I chatted with an Xfinity rep which as usual, gave me the whole pleasantries but did not give me a specific answer. I wanted to know if my numbers could be adjusted since the phone went down 2.50$. 

Why should I pay higher when I can pay lower? It is the same phone, why the change?

Can someone help me? 

[DaveO3]

The simple answer is that no carrier or store Is likely to drop your monthly device cost.  All mobile phones drop in price each year when newer models or versions are released. 

You agreed to buy the K30 which was priced at $180 at the time you bought it and you agreed to pay for it in 24 monthly payments of $7.50.  Since new LG Models have come out they reduced the price of the older K30 to $120, and next model year the price will be reduced again.