Hi,
Maybe you could try returning some of the stuff they sold you that perhaps isn't the best?
Those stick on thermometers are they the round ones? The problem if they are is they have been shown to be very inaccurate which makes it harder to know if your getting things set up right or not.:(
What are your room temperatures and maybe we can find some alternative things you can do as a stopgap measure.
Firt thing that springs to mind are the dimmer switches - at $11 they shouldn't break the bank and are definately better than nothing.
Raising the tank up off the heat mats is another thing to try.
But without the accurate thermometer your really going to struggle to know when it's right.
I would try the heat lamp in the middle (try different wattage bulbs if you have them and don't have a dimmer - but its blind luck if one of them is right) and one heat pad at the warm end and see what the temperatures are in the 2 hides.
A lot of the stuff you could use comes from unexpected places like hides made from plastic plant trays etc from the dollar store.
dr del