No, if you read the detail on the website about the promo it is for new customers. Only way to get the promo would be to get a second line of service and keep that account going for two years to take full advantage of the discount. The other option would be to port out and port back in on a new account but you don't want to do that because you will lose any remaining time left on your current annual plan since Visible doesn't refund unused service. Rarely does Visible have a phone deal for existing customers, I think it has only happened once in the 4 years I have been with Visible.
Here is parts of the terms/details of the promo:
New members, save up to $480 via monthly service credits when they purchase an eligible device. New line required on $45/mo Visible+ Pro plan.
1. Join Visible on a new line of service
2. Purchase an eligible device on device payment or at full retail price
3. Select the monthly Visible+ Pro plan
4. Pay the applicable sales tax on the pre-credit price and activate your service within 30 days
