Taxpayers' plight

Income Tax & Value Added Tax (VAT) of a business are assessed on the basis of sale or turnover. This is unbelievable that in Bangladesh the sale or turnover of a business is always assessed twice by two different govt. departments & the sale or turnover figures assessed by the two departments for the same business is always different! This funny thing is happening because Income tax & VAT is assessed by the income tax officials and the customs department respectively, and there is no co-ordination between the two departments. As a result, a businessman is harassed twice for the same business, which is completely unnecessary.
The customs department should handle the duty & tax on goods being exported or imported, not inland tax (VAT or sales tax). As far as I know, Bangladesh is the only country in the world where inland tax (VAT or sales tax) is collected by the customs department. Around the world, inland tax (VAT or sales tax) is collected by the income tax department along with their regular income tax collection, and in this way a businessman is not harassed twice.