Unless you are losing coolant, which is the question I just asked you, the water pump is not the problem. You just going to throw some money away.
If you are not continuously losing coolant, then it is either a fan or a radiator issue. Most likely the radiator being internally restricted. Turning the heater on just introduces a couple of quarts of cooler coolant so that only lasts for a few minutes.
As far as your deposit is concerned, if you don't click on the accept button, the money stays with the site and I see nothing.
If I was helpful, please click the ACCEPT
button.