Tier 4 visa refused - 8 years cap

Please I need advice regarding my tier 4 refusal. This is very confusing as I am worried on why I got this refusal. I came into the country on a tier 4 visa July 2011, i had two subsequent renewal on tier 4 which is valid till April 2017. My first visa was for taught masters degree while the two subsequent visa was for a professional qualification at level 7. Apparently all my three visas was on level 7 and I have had in time application on all visa. I got offer for PHD and since my present sponsor is a private college, I had to renew from my home country. I submitted my application and did my interview on same day, every thing went fine till I got my refusal sometimes last week. The Eco refused my visa based on just one point, that if my visa was issued, I would have exceeded the 8 years cap for someone studying a PHD. As a matter of fact, the refusal letter clearly contradicts the ECO decision as its says the 5 years cap is not applicable to someone who wants to study a PHD and sponsored by an HEI. Secondly the rules further states that If someone has completed a course leading the the ward a PHD, then the person is restricted to 8 years cap.My sponsor is a university listed as an HEI and I am surprised that my visa was refused despite the fact that I have never done a PHD before, neither have I done a research masters degree. My university has asked me to go ahead with my review because this must be an error as this cap is not applicable to me. I have been studying the tier 4 rules for well over 2 years and I know this cap is not applicable to my situation. I want to believe this must be an error. ECO did not refuse me based on any other reason than the fact that if my visa is granted, I would have exceeded the maximum 8 years allowed. I have read UKCISA and read tier 4 policy guidance, I even went as far as reading the home office staff guidance and all pointed that the 8 year cap only applies to someone who have completed a PHD. Please what do I do, could this be a mistake or has the rules changed over night. Please I need some advice. Thanks

Seems like an ECO error, which should be overturned at AR. Your Tier 4 sponsor is best placed to advise you, which it seems they are doing.