CWT (or more correctly Diners Club - who do the charge recovery) do not know the word "Tax Invoice". And the Indian Call centre doesn't know / care either. After the "bill" is checked and disputed, it has run over time and a nice "Late fee" is added. This costs tens / hundreds monthly. Well done xxxxxx Government. You saved by going to CWT from QBT, but it is now costing more and there is much more staff time to track the problems .