Reptivite DOES contain minerals as well as calcium. The problem (and the reason this is the really hard part of the hobby), is that it contains them in the wrong percentages and proportions.
Don't trash it - it's a decent product, but not for minerals. It's a bit high in vitamin A for regular use, so I use it once or twice a month as a vitamin A supplement - "just in case".
Here is what I use: Rep-cal with D3, Miner-all without D3(Miner-all 0), and herptivite.
Rep-cal is just calcium, and D3 - lots of D3. I take rep-cal, and "cut" it with minerall 0. I usually do a 1:3 ratio of repcal to minerall. Minerall has more minerals than just calcium, which is good. I like to have flexibility, so instead of just using minerall I (with D3), or repcal, I use both. When my animals are outside, in full sun, they get JUST the minerall, so I don't overdose them on D3. When they're growing, or developing eggs, I give them a little extra rep-cal, so they are sure to get all the D3 they need.
i've used both rep-cal and minerall I alone, an dthey both work. I just like the flexibility of basically separating my D3 and mineral supplementation.
Definatly, go to a pet store and find either Miner-all I, or Rep-cal with D3. I'd do it today. Your chameleon is growing fast right now, and it's going to need D3 in order to developproperly.