I have the same issue. My University is recognized by HEC. Its mentioned on HEC's website. HEC also recognizes my University from 2 years prior to it becoming an "autonomous" body.
(1) My University is not listed in WES's accepted Universities from Pakistan. I called in HEC Islamabad Office. Talked with Tahir Farooq sb. He has sent communication to all non-medical Canadian ECA authorities to add my University as "recognized" in their list of accepted Universities from Pakistan.
At the same time, he also mentioned the fact that we in Pakistan can't influence policy of Canadian authorities. Their management makes policies on how they will operate.
(2) ICAS has a very harsh, rigid policy on what its going to accept and not accept. ICAS also won't perform ECA for me. ICAS says, your bachelors was completed prior to your University becoming an "autonomous" body. HEC recognizes your degree since they gave NOC to your University for the period prior to it becoming an "autonomous" body. But we don't recognize that period as legitimate.
I'm still hoping WES will add my university to their list. At the same time, I'm working on getting ECA done through UToronto CES. I'm not sure if UToronto CES will do it for me. But I have to try. Try and fail is better than not trying at all.