My bill increase over night from $75 to $139 for very small apartment

My bill has been $75/month for the past three years and just jumped to $139... nearly double, with no change to my service. I'm assuming my promotional rate expired.

I've been a reliable customer for three years and would like to stay, but $139 isn't sustainable for me. What current promotions or loyalty pricing can be applied to my account? I'm happy to look at a different speed tier if that's what it takes to get back near my previous rate.

If there's nothing available, could someone point me to the retention team?