Number porting is available to all. Non issue.
Keeping all services currently in your bundle may improve your bargaining position.
To start off the negotiation, praise the service. The CSR will thank you for being a valued customer. Then bring up your budgetary constraints. Explain that you'd like to keep the bundle but the post promotion price is too high. Ask for a discount.
If that doesn't work, threaten to cancel and always mention there is another provider that will offer you a better deal.
Do not fall for the "oh, we can offer you free movies for 6 months but at the new price"..
The way I look at it, a budget is a budget. It does not matter how many free services they offer. If the number is too much for your finances it is too much.