Unfair higher pricing for existing customers compared to new customers

I am very dissatisfied that after contacting customer service as an existing customer with home internet service and two phone lines,

Comcast/Xfinity will not match new customer lower price offers for existing customers.

This is an unfair and unprofessional way to do business with a customer since 2019.

Last year, when my wife tried to get a deal on Internet, a Comcast/Xfinity employee made a mistake and changed our plan to 200 mbps, which we did not request.

We originally requested 75 mbps and it was incorrectly approved for 200 mbps.

When my wife raised a complaint, they returned the money for the extra charge however, they did not change the plan.

Now we want to downgrade the plan to 75 mbps and it is priced higher than the 200 mbps plan!

So it appears Xfinity may be intentionally screwing us not to downgrade service for a lower price.

Not only that, we compared the Xfinity 75 mbps plan for a new customers and it costs them less than 45% than ours!

We are 4 year loyal customers with a proven on time payment record! Such a disappointment! 

So, if we will be asked to pay more, what extra value will the company provide? What do we get in return?