The short answer is that "The Rape of the Lock" is both mock epic and mock-heroic epic.
Mock epic and Mock-heroic epic are often considered the same thing. Pope's subtitle is "An Heroi-Comical Poem." However, anthologies tend to call it a mock epic. But I think both terms apply. It mocks the epic style. There are gods (Ariel and Umbriel), there is a battle (with teacups), there is a descent into the underworld (the Cave of Spleen) and there are heroes (Belinda and the Baron specifically, but it is a war between the sexes). The apotheosis, a divine glorification of the hero or the hero's deeds, occurs when the lock of hair flies up, becoming a celestial body such as a star.
Depending on your interpretation, you could say that Belinda and the Baron are heroes, similar (in mocking style) to Hector and Achilles in The Illiad. You might also consider Ariel a supernatural hero since it is his job to protect Belinda. But in epic style, Belinda fits the heroic role more than any other character because the act of putting on her makeup is actually symbolic of putting on armor. She "arms" herself at the end of Canto 1:
Here files of pins extend their shining rows,
Puffs, powders, patches, Bibles, billet-dout.
Now awful Beauty puts on all its arms; (137-39).
It is generally agreed that the sylphs are the gods and Belinda, the Baron and the other humans are the mock heroes. These heroes don't seem heroic but that is the point; they are being mocked. This is also called bathos; this means to present a common or trivial event in an exalted, epic style. The result is that the characters look ridiculous.
I suppose if you wanted to differentiate between mock epic and mock-heroic epic, the former would focus most of its mocking on the epic style and the latter (mock-heroic) would focus most of its mocking on the characters: the "heroes." I think "The Rape of the Lock" does both, but since it is a criticism of early 18th century upper-class twits, the people themselves, you could say the focus leans toward criticism of the so-called heroes, so maybe it is slightly more mock-heroic.