If you’re only spending $15/day then absolutely hiring an agency is a waste of your time. You have such a small budget that they can’t do any meaningful optimizations because you’re getting data at a snails pace. Not to mention that at that price point, you’re also probably paying more per month in fees than you are on traffic, which is a losing value proposition for you.

This isn’t the “agency not doing their job right”, this is you making a poor business decision. Your best options are to either try and get your money back, or properly fund your campaigns. Anything else will be a waste of both time and money.