AT&T DSL → At&t DSLAM Cap

I used to have 6mps DSL with At&t several years ago, but downgraded to 1.5. I called to upgrade back to 6 or at least 3 and was informed (after pulling teeth and an act of congress) that the engineers have placed a cap on the dslam that I connect to. They told me that the dslam was full, but the tech readout says thats not the case. My current speed according to the tech readout is 1536, the max allowed is 7163200...Why are they lying to me about upgrading my speed? I though it would be beneficial to them for me to overpay for their crap services every month (they are the only internet service providers in my area other than satellite). I know about the VIP project, but I'm already using the legacy dsl bonded copper, I don't understand how upgrading me to a different speed impedes on anything with VIP.

Is U-verse available at your address? If so, they may be looking to pressure you into getting U-verse, by artificially limiting legacy DSL connection upgrades for your DSLAM.

Why? Because they don't want to run the legacy DSL network anymore. Yes, they could upgrade you 6M with the click of the mouse, but they cannot be bothered. (Even in non-uverse areas, they'd rather lose a customer than maintain the aging legacy gear.)

it's more of the back end hardware/bandwidth available. If they capped it for capacity, they typically cap it due to bandwidth available in the area.