FNB Revolving Loan has hidden criteria in addition to the 15% repayment threshold!

I have a revolving loan with FNB. Last week I paid in funds to reach 15% of my limit - which I thought is the threshold to allow me access to withdraw from the facility. To my surprise this did not happen. I contacted my private banker and explained to me that there is additional criteria in additon to the 15%! This came as a surprise as I do not recall that being part of the package. Had I known that this would be the case, I surely would not have deposited additional funds at a time I needed to access more funds! I also understand that FNB has a new revolcing facility that works better - my question is why have I not been migrated to this facility with a "sweep" function that would allow me to access funds when I need them now??? I have never had issues with FNB but I am disappointed that thiswas not disclosed upfront!