Trying different networks isn’t likely to be the answer to your problem. It is most likely that your failure is due to improper implementation, not an issue with your selected channel.
Regardless of which network you go with, success depends upon how well you execute your marketing plan, and how well you have chosen your strategy. It takes hundreds of hours to learn how to run a proper PPC campaign. Developing and tweaking your marketing plan can take much time as well. Switching networks is just going to lengthen the learning curve, not shorten it.
There is a lot more to managing a PPC campaign than simply setting up some ads and hoping they make you money. Since you have run several campaigns already, you should have some data gathered. Have you gathered enough data to make actionable adjustments? What insights have you gained from your data?
Does the process you have in place now allow you to test, analyze results, gain insights, make improvements based on those insights and repeat that cycle over and over? If not, this is what you should seek first, switching networks isn’t the answer.