Domino s pizza - Excess billing amount

Dear Sir/ Mam,

I am forced to write this mail as from the last three times whenever I am ordering pizza from Domino's I am facing the problem of excess bill amount . As when I place the order I receive a message to pay rupees ***/- but when I receive the order the bill amount gets automatically increased to rupees ***/- . This is not an one time issue it is happening again and again due to with I feel ashamed when I send someone else to take the delivery from the delivery boy . As the other person thinks that I have given him less money or if I can't afford then why I place the order.
And all this is happening due to failure on your part.

Now please do let me know what can be done for the humiliation suffered by me