Your time is up. It may have been one, two, or if you are especially lucky — three years since you signed up for Charter Spectrum service. But your temporary reprieve from the high price of cable is over.

The bad news arrives in a letter:

Thank you for being a Spectrum customer. When you signed up for your services, you received a promotional discounted rate on your bill. This promotion is coming to an end. However, as a valued customer we are pleased to offer a new promotion for an additional year.

Spectrum certainly is pleased. You may not be. To avoid shocking you too much, the company does not provide a new “out the door” price. They wait until they send you your first post-promotion bill. The letter also does not remind you what you were paying, it breaks out the price of each component service of your bundle for the following 12 months in an effort to lessen the surprise.

For most Spectrum customers on a basic, new customer promotion lasting one year, the rate change is substantial — once you add it all up.

For a customer subscribed to Standard Spectrum TV with two DVR boxes, Internet Ultra (400/20 Mbps), and Spectrum Voice, here is what you can expect (prices and promotions may vary):

• Standard Spectrum TV: Your promotional rate of $54.98 will rise to $86.97, an increase of $31.99.
• Internet Ultra: The promotional triple-play bundled price of $54.99 increases to $74.99, up $20.
• Spectrum Voice: The bundled price of $29.99 will decrease to $19.99, a savings of $10.

Spectrum Voice, Charter’s digital home phone line product, is the most vulnerable part of their triple play bundle. Scores of customers drop landline service at the end of a promotion because, in many cases, having the landline as part of a triple play package either came free (or almost free), or actually reduced the price of the bundle. By offering a lower rate going forward, Charter is making a token effort to convince customers not to abandon voice service, but as the company’s landline disconnects continue to accelerate, it clearly isn’t an effective tactic.

The letter also ignores Charter’s ever-rising Broadcast TV Fee, now $11.99 a month, and is compulsory for all cable TV customers. So the old monthly promotional rate of $155.75 for this particular package will rise to about $193.94, a difference of $38.19 a month. After a second 12 months, prices generally reset even higher to the published “rack rate.”

Since Charter took control of Time Warner Cable and Bright House Networks, efforts by customers to negotiate a lower rate got much tougher, but the company’s customer retention efforts have stepped up slightly over the last year. You should still expect to pay more than you did before, but it is often possible to negotiate a slightly better deal by threatening to cancel service. Some customers report more success discussing the matter in a Spectrum cable store, cable modem and set top boxes in hand. But do not be surprised if they shrug their shoulders and agree to your request to cancel your account on the spot. Spectrum, like many cable companies, has gotten pickier about who they offer promotions to, and are willing to say goodbye to barely profitable customers, especially those only subscribed to cable TV.