Entry level bikes are designed to be sold at a price point. What this means is, the parts are spec'd out to at least be functional at the lowest possible cost. In your case the brakes were the parts that are the least functional. They still work, but not great. The good news is that the brake pads are one of the cheapest upgrades you can make. With a minimum of tools and skill you can change the pads. Avoid buying pads at Walmart, Target etc as these are likely similar in quality to what you have. I would suggest you visit a local shop see what they carry and ask for the best brakes you can get in your price range.