Stop jerking me around

You give your customers no simple way to lodge a complaint in writing to have evidence to protect ourselves. So here goes:

My speed was increased from 500Mbps to 1000Mbps without my permission and the price greatly increased. I phoned and the operator allegedly fixed this but did not send a confirmatory e-mail, as agreed, nor a new contract. This is totally unacceptable.

Now I am only getting 25Mbps. I am paying for 500Mbps. This looks like retribution. This is totally unacceptable.

Every year I have some major issue with you. Enough. There is only so much poor service I will tolerate regardless of price. Just cancel my contract and give me the date your service will stop.