Unfortunately business rates are out of the control of SBC, they're set by some government agency based on the value of the property. Currently council only get 50% and is it's not until 2020 that councils will able to keep 100% of the business rates income (assuming Osborne's plans haven't been changed/scraped). However, I expect the government will cut the amount of money it gives the council as a result.
Swindon suffers because it's in commuting distance of Bristol/Bath, Oxford, Reading and London so property prices and hence business rates are too high for a town like Swindon. If Swindon was in the north somewhere there is no way property prices would be as expensive.