This is what I have to date.
There is a small storefront in Higuey, 35 miles from Breezes. The name is "Centro De Rehabilitacion" located at Av. Laguna Llana #83, in front of the Basilica. The phone is 809-554-1456 It does have a wheelchair. The rent is RD $600 per month, no mention of a security deposit. English is not spoken there.
To be truthful, its operation is very Dominican. The employees could not answer the very basic questions, such as: Are there any sillas de ruedas (wheelchairs) available to rent? What is the tariff? without having to make a phone call to the boss, if you catch my drift.
What PJT was able to find out, the only good wheelchair is rented. The backup chair was functional, but the plastic armrest on the right side needed repair. They need an advance notice.
Keep annoying the hotel.
Regards, PJT